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16 BIT MATH (AVR 202)

                                    ;**** A P P L I C A T I O N   N O T E   A V R 2 0 2 ************************
                                    ;*
                                    ;* Title:		16-bit Arithmetics
                                    ;* Version:		1.1
                                    ;* Last updated:	97.07.04
                                    ;* Target:		AT90Sxxxx (All AVR Devices)
                                    ;*
                                    ;* Support E-mail:	avr@atmel.com
                                    ;*
                                    ;* DESCRIPTION
                                    ;* This application note lists applications for the following 
                                    ;* Add/Subtract/Compare operations:
                                    ;*
                                    ;* "add16"	ADD 16+16	
                                    ;* "adddi16"	ADD 16+Immediate(16)
                                    ;* "sub16"	SUB 16-16
                                    ;* "subi16"     SUB 16-Immediate(16)
                                    ;* "cp16"	COMPARE 16/16 
                                    ;* "cpi16"    	COMPARE 16/Immediate 
                                    ;* "neg16"      NEGATION 16
                                    ;*
                                    ;***************************************************************************
                                    
                                    .cseg
                                    	ldi	r16,0x12	;Set up some registers to show usage of
                                    	ldi	r17,0x34	;the subroutines below.
                                    	ldi	r18,0x56	;All expected results are presented as 
                                    	ldi	r19,0x78	;comments
                                    
                                    
                                    ;***************************************************************************
                                    ;* 
                                    ;* "add16" - Adding 16-bit registers
                                    ;*
                                    ;* This example adds the two pairs of register variables (add1l,add1h)
                                    ;* and (add2l,add2h)  The result is placed in (add1l, add1h).
                                    ;*
                                    ;* Number of words	:2
                                    ;* Number of cycles	:2
                                    ;* Low registers used	:None
                                    ;* High registers used	:4
                                    ;*
                                    ;* Note: The sum and the addend share the same register.  This causes the
                                    ;* addend to be overwritten by the sum.
                                    ;*
                                    ;***************************************************************************
                                    
                                    ;**** Register Variables
                                    .def add1l = r16
                                    .def add1h = r17
                                    .def add2l = r18
                                    .def add2h = r19
                                    
                                    ;***** Code
                                    add16:	add	add1l, add2l		;Add low bytes
                                    	adc	add1h, add2h		;Add high bytes with carry
                                    	;Expected result is 0xAC68
                                    
                                    
                                    
                                    ;***************************************************************************
                                    ;* 
                                    ;* "addi16" - Adding 16-bit register with immediate
                                    ;*
                                    ;* This example adds a register variable (addi1l,addi1h) with an 
                                    ;* immediate 16-bit number defined with .equ-statement.   The result is
                                    ;* placed in (addi1l, addi1h).
                                    ;*
                                    ;* Number of words	:2
                                    ;* Number of cycles	:2
                                    ;* Low registers used	:None
                                    ;* High registers used	:2
                                    ;*
                                    ;* Note: The sum and the addend share the same register.  This causes the
                                    ;* addend to be overwritten by the sum.
                                    ;*
                                    ;***************************************************************************
                                    
                                    ;***** Register Variables
                                    .def addi1l = r16
                                    .def addi1h = r17
                                    
                                    ;***** Immediate 16-bit number
                                    .equ addi2 = 0x1234
                                    
                                    ;***** Code
                                    addi16:	subi	add1l, low(-addi2)	;Add low byte ( x -(-y)) = x + y
                                    	sbci	add1h, high(-addi2)	;Add high byte with carry
                                    	;Expected result is 0xBE9C
                                    
                                    
                                    
                                    ;***************************************************************************
                                    ;* 
                                    ;* "sub16" - Subtracting 16-bit registers 
                                    ;*
                                    ;* This example subtracts two pairs of register variables (sub1l,sub1h) 
                                    ;* from (sub2l, sub2h)  The result is stored in registers sub1l, sub1h.
                                    ;*
                                    ;* Number of words	:2
                                    ;* Number of cycles	:2
                                    ;* Low registers used	:None
                                    ;* High registers used	:4
                                    ;*
                                    ;* Note: The result and "sub1" share the same register.  This causes "sub1"
                                    ;* to be overwritten by the result.
                                    ;*
                                    ;***************************************************************************
                                    
                                    ;***** Register Variables
                                    .def sub1l = r16
                                    .def sub1h = r17
                                    .def sub2l = r18
                                    .def sub2h = r19
                                    
                                    ;***** Code
                                    sub16:	sub	sub1l,sub2l		;Subtract low bytes
                                    	sbc	sub1h,sub2h		;Add high byte with carry
                                    	;Expected result is 0x4646
                                    
                                    
                                    
                                    ;***************************************************************************
                                    ;* 
                                    ;* "subi16" - Subtracting immediate 16-bit number from a 16-bit register
                                    ;*
                                    ;* This example subtracts the immediate 16-bit number subi2 from the
                                    ;* 16-bit register (subi1l,subi1h)  The result is placed in registers
                                    ;* subi1l, subi1h.
                                    ;*
                                    ;* Number of words	:2
                                    ;* Number of cycles	:2
                                    ;* Low registers used	:None
                                    ;* High registers used	:2
                                    ;*
                                    ;* Note: The result and "subi1" share the same register.  This causes 
                                    ;* "subi1" to be overwritten by the result.
                                    ;*
                                    ;***************************************************************************
                                    
                                    ;***** Register Variables
                                    .def subi1l = r16
                                    .def subi1h = r17
                                    
                                    ;***** Immediate 16-bit number
                                    .equ subi2 = 0x1234
                                    
                                    ;***** Code
                                    subi16:	subi	subi1l,low(subi2)	;Subtract low bytes
                                    	sbci	subi1h,high(subi2)	;Subtract high byte with carry
                                    	;Expected result is 0x3412
                                    
                                    
                                    
                                    ;***************************************************************************
                                    ;* 
                                    ;* "cp16" - Comparing two 16-bit numbers 
                                    ;*
                                    ;* This example compares the register pairs (cp1l,cp1h) with the register
                                    ;* pairs (cp2l,cp2h)  If they are equal the zero flag is set(one) 
                                    ;* otherwise it is cleared(zero)
                                    ;*
                                    ;* Number of words	:2
                                    ;* Number of cycles	:2
                                    ;* Low registers used	:None
                                    ;* High registers used	:4
                                    ;*
                                    ;* Note: The contents of "cp1" will be overwritten.
                                    ;*
                                    ;***************************************************************************
                                    
                                    ;***** Register Variables
                                    .def cp1l = r16
                                    .def cp1h = r17
                                    .def cp2l = r18
                                    .def cp2h = r19
                                    
                                    ;***** Code
                                    cp16:	cp	cp1l,cp2l	;Compare low byte
                                    	cpc	cp1h,cp2h	;Compare high byte with carry from
                                    				;previous operation
                                    ncp16:
                                    	;Expected result is Z=0
                                    
                                    
                                    
                                    ;***************************************************************************
                                    ;* 
                                    ;* "cpi16" - Comparing 16-bit register with 16-bit immediate 
                                    ;*
                                    ;* This example compares the register pairs (cpi1l,cpi1h) with the value
                                    ;* cpi2.  If they are equal the zero flag is set(one), otherwise it is 
                                    ;* cleared(zero). This is enabled by the AVR's zero propagation. Carry is
                                    ;* also set if the result is negative. This means that all conditional
                                    ;* branch instructions can be used after the comparison. 
                                    ;*
                                    ;* Number of words	:3
                                    ;* Number of cycles	:3
                                    ;* Low registers used	:None
                                    ;* High registers used	:3
                                    ;*
                                    ;*
                                    ;***************************************************************************
                                    
                                    ;***** Register Variables
                                    .def cp1l =r16
                                    .def cp1h =r17
                                    .def c_tmp=r18 
                                    .equ cp2 = 0x3412		;Immediate to compare with
                                    
                                    ;***** Code
                                    cpi16:	cpi	cp1l,low(cp2)	;Compare low byte
                                    	ldi	c_tmp,high(cp2)	;
                                    	cpc	cp1h,c_tmp	;Compare high byte
                                    
                                    	;Expected result is Z=1, C=
                                    
                                    
                                    
                                    ;***************************************************************************
                                    ;* 
                                    ;* "neg16" - Negating 16-bit register
                                    ;*
                                    ;* This example negates the register pair (ng1l,ng1h)  The result will 
                                    ;* overwrite the register pair.
                                    ;*
                                    ;* Number of words	:4
                                    ;* Number of cycles	:4
                                    ;* Low registers used	:None
                                    ;* High registers used	:2
                                    ;*
                                    ;***************************************************************************
                                    
                                    ;***** Register Variables
                                    .def ng1l = r16
                                    .def ng1h = r17
                                    
                                    ;***** Code
                                    ng16:	
                                    	com	ng1l		;Invert low byte	;Calculated by 
                                    	com	ng1h		;Invert high byte	;incverting all 
                                    	subi	ng1l,low(-1)	;Add 0x0001, low byte	;bits then adding
                                    	sbci	ng1h,high(-1)	;Add high byte		;one (0x0001)
                                    	;Expected result is 0xCBEE
                                    
                                    
                                    ;***************************************************************************
                                    ;*
                                    ;* End of examples.
                                    ;*
                                    ;***************************************************************************
                                    
                                    
                                    forever:rjmp	forever
                                    
                                    
                                 

Programming the AVR Microcontrollers in Assember Machine Language

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Atmel AVR From Wikipedia, the free encyclopedia (Redirected from Avr) Jump to: navigation, search The AVRs are a family of RISC microcontrollers from Atmel. Their internal architecture was conceived by two students: Alf-Egil Bogen and Vegard Wollan, at the Norwegian Institute of Technology (NTH] and further developed at Atmel Norway, a subsidiary founded by the two architects. Atmel recently released the Atmel AVR32 line of microcontrollers. These are 32-bit RISC devices featuring SIMD and DSP instructions, along with many additional features for audio and video processing, intended to compete with ARM based processors. Note that the use of "AVR" in this article refers to the 8-bit RISC line of Atmel AVR Microcontrollers. The acronym AVR has been reported to stand for Advanced Virtual RISC. It's also rumoured to stand for the company's founders: Alf and Vegard, who are evasive when questioned about it. Contents [hide] 1 Device Overview 1.1 Program Memory 1.2 Data Memory and Registers 1.3 EEPROM 1.4 Program Execution 1.5 Speed 2 Development 3 Features 4 Footnotes 5 See also 6 External Links 6.1 Atmel Official Links 6.2 AVR Forums & Discussion Groups 6.3 Machine Language Development 6.4 C Language Development 6.5 BASIC & Other AVR Languages 6.6 AVR Butterfly Specific 6.7 Other AVR Links [edit] Device Overview The AVR is a Harvard architecture machine with programs and data stored and addressed separately. Flash, EEPROM, and SRAM are all integrated onto a single die, removing the need for external memory (though still available on some devices). [edit] Program Memory Program instructions are stored in semi-permanent Flash memory. Each instruction for the AVR line is either 16 or 32 bits in length. The Flash memory is addressed using 16 bit word sizes. The size of the program memory is indicated in the naming of the device itself. For instance, the ATmega64x line has 64Kbytes of Flash. Almost all AVR devices are self-programmable. [edit] Data Memory and Registers The data address space consists of the register file, I/O registers, and SRAM. The AVRs have thirty-two single-byte registers and are classified as 8-bit RISC devices. The working registers are mapped in as the first thirty-two memory spaces (000016-001F16) followed by the 64 I/O registers (002016-005F16). The actual usable RAM starts after both these sections (address 006016). (Note that the I/O register space may be larger on some more extensive devices, in which case memory mapped I/O registers will occupy a portion of the SRAM.) Even though there are separate addressing schemes and optimized opcodes for register file and I/O register access, all can still be addressed and manipulated as if they were in SRAM. [edit] EEPROM Almost all devices have on-die EEPROM. This is most often used for long-term parameter storage to be retrieved even after cycling the power of the device. [edit] Program Execution Atmel's AVRs have a single level pipeline design. The next machine instruction is fetched as the current one is executing. Most instructions take just one or two clock cycles, making AVRs relatively fast among the eight-bit microcontrollers. The AVR family of processors were designed for the efficient execution of compiled C code. The AVR instruction set is more orthogonal than most eight-bit microcontrollers, however, it is not completely regular: Pointer registers X, Y, and Z have addressing capabilities that are different from each other. Register locations R0 to R15 have different addressing capabilities than register locations R16 to R31. I/O ports 0 to 31 have different addressing capabilities than I/O ports 32 to 63. CLR affects flags, while SER does not, even though they are complementary instructions. CLR set all bits to zero and SER sets them to one. (Note though, that neither CLR nor SER are native instructions. Instead CLR is syntactic sugar for [produces the same machine code as] EOR R,R while SER is syntactic sugar for LDI R,$FF. Math operations such as EOR modify flags while moves/loads/stores/branches such as LDI do not.) [edit] Speed The AVR line can normally support clock speeds from 0-16MHz, with some devices reaching 20MHz. Lower powered operation usually requires a reduced clock speed. All AVRs feature an on-chip oscillator, removing the need for external clocks or resonator circuitry. Because many operations on the AVR are single cycle, the AVR can achieve up to 1MIPS per MHz. [edit] Development AVRs have a large following due to the free and inexpensive development tools available, including reasonably priced development boards and free development software. The AVRs are marketed under various names that share the same basic core but with different peripheral and memory combinations. Some models (notably, the ATmega range) have additional instructions to make arithmetic faster. Compatibility amongst chips is fairly good. See external links for sites relating to AVR development. [edit] Features Current AVRs offer a wide range of features: RISC Core Running Many Single Cycle Instructions Multifunction, Bi-directional I/O Ports with Internal, Configurable Pull-up Resistors Multiple Internal Oscillators Internal, Self-Programmable Instruction Flash Memory up to 256K In-System Programmable using ICSP, JTAG, or High Voltage methods Optional Boot Code Section with Independent Lock Bits for Protection Internal Data EEPROM up to 4KB Internal SRAM up to 8K 8-Bit and 16-Bit Timers PWM Channels & dead time generator Lighting (PWM Specific) Controller models Dedicated IC Compatible Two-Wire Interface (TWI) Synchronous/Asynchronous Serial Peripherals (UART/USART) (As used with RS-232,RS-485, and more) Serial Peripheral Interface (SPI) CAN Controller Support USB Controller Support Proper High-speed hardware & Hub controller with embedded AVR. Also freely available low-speed (HID) software emulation Ethernet Controller Support Universal Serial Interface (USI) for Two or Three-Wire Synchronous Data Transfer Analog Comparators LCD Controller Support 10-Bit A/D Converters, with multiplex of up to 16 channels Brownout Detection Watchdog Timer (WDT) Low-voltage Devices Operating Down to 1.8v Multiple Power-Saving Sleep Modes picoPower Devices Atmel AVR assembler programming language Atmel AVR machine programming language Atmel AVR From Wikipedia, the free encyclopedia (Redirected from Avr) Jump to: navigation, search The AVRs are a family of RISC microcontrollers from Atmel. Their internal architecture was conceived by two students: Alf-Egil Bogen and Vegard Wollan, at the Norwegian Institute of Technology (NTH] and further developed at Atmel Norway, a subsidiary founded by the two architects. Atmel recently released the Atmel AVR32 line of microcontrollers. These are 32-bit RISC devices featuring SIMD and DSP instructions, along with many additional features for audio and video processing, intended to compete with ARM based processors. Note that the use of "AVR" in this article refers to the 8-bit RISC line of Atmel AVR Microcontrollers. The acronym AVR has been reported to stand for Advanced Virtual RISC. It's also rumoured to stand for the company's founders: Alf and Vegard, who are evasive when questioned about it. Contents [hide] 1 Device Overview 1.1 Program Memory 1.2 Data Memory and Registers 1.3 EEPROM 1.4 Program Execution 1.5 Speed 2 Development 3 Features 4 Footnotes 5 See also 6 External Links 6.1 Atmel Official Links 6.2 AVR Forums & Discussion Groups 6.3 Machine Language Development 6.4 C Language Development 6.5 BASIC & Other AVR Languages 6.6 AVR Butterfly Specific 6.7 Other AVR Links [edit] Device Overview The AVR is a Harvard architecture machine with programs and data stored and addressed separately. Flash, EEPROM, and SRAM are all integrated onto a single die, removing the need for external memory (though still available on some devices). [edit] Program Memory Program instructions are stored in semi-permanent Flash memory. Each instruction for the AVR line is either 16 or 32 bits in length. The Flash memory is addressed using 16 bit word sizes. The size of the program memory is indicated in the naming of the device itself. For instance, the ATmega64x line has 64Kbytes of Flash. Almost all AVR devices are self-programmable. [edit] Data Memory and Registers The data address space consists of the register file, I/O registers, and SRAM. The AVRs have thirty-two single-byte registers and are classified as 8-bit RISC devices. The working registers are mapped in as the first thirty-two memory spaces (000016-001F16) followed by the 64 I/O registers (002016-005F16). The actual usable RAM starts after both these sections (address 006016). (Note that the I/O register space may be larger on some more extensive devices, in which case memory mapped I/O registers will occupy a portion of the SRAM.) Even though there are separate addressing schemes and optimized opcodes for register file and I/O register access, all can still be addressed and manipulated as if they were in SRAM. [edit] EEPROM Almost all devices have on-die EEPROM. This is most often used for long-term parameter storage to be retrieved even after cycling the power of the device. [edit] Program Execution Atmel's AVRs have a single level pipeline design. The next machine instruction is fetched as the current one is executing. Most instructions take just one or two clock cycles, making AVRs relatively fast among the eight-bit microcontrollers. The AVR family of processors were designed for the efficient execution of compiled C code. The AVR instruction set is more orthogonal than most eight-bit microcontrollers, however, it is not completely regular: Pointer registers X, Y, and Z have addressing capabilities that are different from each other. Register locations R0 to R15 have different addressing capabilities than register locations R16 to R31. I/O ports 0 to 31 have different addressing capabilities than I/O ports 32 to 63. CLR affects flags, while SER does not, even though they are complementary instructions. CLR set all bits to zero and SER sets them to one. (Note though, that neither CLR nor SER are native instructions. Instead CLR is syntactic sugar for [produces the same machine code as] EOR R,R while SER is syntactic sugar for LDI R,$FF. Math operations such as EOR modify flags while moves/loads/stores/branches such as LDI do not.) [edit] Speed The AVR line can normally support clock speeds from 0-16MHz, with some devices reaching 20MHz. Lower powered operation usually requires a reduced clock speed. All AVRs feature an on-chip oscillator, removing the need for external clocks or resonator circuitry. Because many operations on the AVR are single cycle, the AVR can achieve up to 1MIPS per MHz. [edit] Development AVRs have a large following due to the free and inexpensive development tools available, including reasonably priced development boards and free development software. The AVRs are marketed under various names that share the same basic core but with different peripheral and memory combinations. Some models (notably, the ATmega range) have additional instructions to make arithmetic faster. Compatibility amongst chips is fairly good. See external links for sites relating to AVR development. [edit] Features Current AVRs offer a wide range of features: RISC Core Running Many Single Cycle Instructions Multifunction, Bi-directional I/O Ports with Internal, Configurable Pull-up Resistors Multiple Internal Oscillators Internal, Self-Programmable Instruction Flash Memory up to 256K In-System Programmable using ICSP, JTAG, or High Voltage methods Optional Boot Code Section with Independent Lock Bits for Protection Internal Data EEPROM up to 4KB Internal SRAM up to 8K 8-Bit and 16-Bit Timers PWM Channels & dead time generator Lighting (PWM Specific) Controller models Dedicated IC Compatible Two-Wire Interface (TWI) Synchronous/Asynchronous Serial Peripherals (UART/USART) (As used with RS-232,RS-485, and more) Serial Peripheral Interface (SPI) CAN Controller Support USB Controller Support Proper High-speed hardware & Hub controller with embedded AVR. Also freely available low-speed (HID) software emulation Ethernet Controller Support Universal Serial Interface (USI) for Two or Three-Wire Synchronous Data Transfer Analog Comparators LCD Controller Support 10-Bit A/D Converters, with multiplex of up to 16 channels Brownout Detection Watchdog Timer (WDT) Low-voltage Devices Operating Down to 1.8v Multiple Power-Saving Sleep Modes picoPower Devices Atmel AVR assembler programming language Atmel AVR machine programming language Atmel AVR From Wikipedia, the free encyclopedia (Redirected from Avr) Jump to: navigation, search The AVRs are a family of RISC microcontrollers from Atmel. Their internal architecture was conceived by two students: Alf-Egil Bogen and Vegard Wollan, at the Norwegian Institute of Technology (NTH] and further developed at Atmel Norway, a subsidiary founded by the two architects. Atmel recently released the Atmel AVR32 line of microcontrollers. These are 32-bit RISC devices featuring SIMD and DSP instructions, along with many additional features for audio and video processing, intended to compete with ARM based processors. Note that the use of "AVR" in this article refers to the 8-bit RISC line of Atmel AVR Microcontrollers. The acronym AVR has been reported to stand for Advanced Virtual RISC. It's also rumoured to stand for the company's founders: Alf and Vegard, who are evasive when questioned about it. Contents [hide] 1 Device Overview 1.1 Program Memory 1.2 Data Memory and Registers 1.3 EEPROM 1.4 Program Execution 1.5 Speed 2 Development 3 Features 4 Footnotes 5 See also 6 External Links 6.1 Atmel Official Links 6.2 AVR Forums & Discussion Groups 6.3 Machine Language Development 6.4 C Language Development 6.5 BASIC & Other AVR Languages 6.6 AVR Butterfly Specific 6.7 Other AVR Links [edit] Device Overview The AVR is a Harvard architecture machine with programs and data stored and addressed separately. Flash, EEPROM, and SRAM are all integrated onto a single die, removing the need for external memory (though still available on some devices). [edit] Program Memory Program instructions are stored in semi-permanent Flash memory. Each instruction for the AVR line is either 16 or 32 bits in length. The Flash memory is addressed using 16 bit word sizes. The size of the program memory is indicated in the naming of the device itself. For instance, the ATmega64x line has 64Kbytes of Flash. Almost all AVR devices are self-programmable. [edit] Data Memory and Registers The data address space consists of the register file, I/O registers, and SRAM. The AVRs have thirty-two single-byte registers and are classified as 8-bit RISC devices. The working registers are mapped in as the first thirty-two memory spaces (000016-001F16) followed by the 64 I/O registers (002016-005F16). The actual usable RAM starts after both these sections (address 006016). (Note that the I/O register space may be larger on some more extensive devices, in which case memory mapped I/O registers will occupy a portion of the SRAM.) Even though there are separate addressing schemes and optimized opcodes for register file and I/O register access, all can still be addressed and manipulated as if they were in SRAM. [edit] EEPROM Almost all devices have on-die EEPROM. This is most often used for long-term parameter storage to be retrieved even after cycling the power of the device. [edit] Program Execution Atmel's AVRs have a single level pipeline design. The next machine instruction is fetched as the current one is executing. Most instructions take just one or two clock cycles, making AVRs relatively fast among the eight-bit microcontrollers. The AVR family of processors were designed for the efficient execution of compiled C code. The AVR instruction set is more orthogonal than most eight-bit microcontrollers, however, it is not completely regular: Pointer registers X, Y, and Z have addressing capabilities that are different from each other. Register locations R0 to R15 have different addressing capabilities than register locations R16 to R31. I/O ports 0 to 31 have different addressing capabilities than I/O ports 32 to 63. CLR affects flags, while SER does not, even though they are complementary instructions. CLR set all bits to zero and SER sets them to one. (Note though, that neither CLR nor SER are native instructions. Instead CLR is syntactic sugar for [produces the same machine code as] EOR R,R while SER is syntactic sugar for LDI R,$FF. Math operations such as EOR modify flags while moves/loads/stores/branches such as LDI do not.) [edit] Speed The AVR line can normally support clock speeds from 0-16MHz, with some devices reaching 20MHz. Lower powered operation usually requires a reduced clock speed. All AVRs feature an on-chip oscillator, removing the need for external clocks or resonator circuitry. Because many operations on the AVR are single cycle, the AVR can achieve up to 1MIPS per MHz. [edit] Development AVRs have a large following due to the free and inexpensive development tools available, including reasonably priced development boards and free development software. The AVRs are marketed under various names that share the same basic core but with different peripheral and memory combinations. Some models (notably, the ATmega range) have additional instructions to make arithmetic faster. Compatibility amongst chips is fairly good. See external links for sites relating to AVR development. [edit] Features Current AVRs offer a wide range of features: RISC Core Running Many Single Cycle Instructions Multifunction, Bi-directional I/O Ports with Internal, Configurable Pull-up Resistors Multiple Internal Oscillators Internal, Self-Programmable Instruction Flash Memory up to 256K In-System Programmable using ICSP, JTAG, or High Voltage methods Optional Boot Code Section with Independent Lock Bits for Protection Internal Data EEPROM up to 4KB Internal SRAM up to 8K 8-Bit and 16-Bit Timers PWM Channels & dead time generator Lighting (PWM Specific) Controller models Dedicated IC Compatible Two-Wire Interface (TWI) Synchronous/Asynchronous Serial Peripherals (UART/USART) (As used with RS-232,RS-485, and more) Serial Peripheral Interface (SPI) CAN Controller Support USB Controller Support Proper High-speed hardware & Hub controller with embedded AVR. Also freely available low-speed (HID) software emulation Ethernet Controller Support Universal Serial Interface (USI) for Two or Three-Wire Synchronous Data Transfer Analog Comparators LCD Controller Support 10-Bit A/D Converters, with multiplex of up to 16 channels Brownout Detection Watchdog Timer (WDT) Low-voltage Devices Operating Down to 1.8v Multiple Power-Saving Sleep Modes picoPower Devices Atmel AVR assembler programming language Atmel AVR machine programming language