Datasheet AT90S8515 Datasheet (ATMEL)

Features

•

AVR - High Performance and Low Power RISC Architecture

•

118 Powerful Instructions - Most Single Clock Cycle Execution

•

8K bytes of In-System Reprogrammable Flash

– SPI Serial Interface for Program Downloading
– Endurance: 1,000 Write/Eras e Cycles

•

512 bytes EEPROM

– Endurance: 100,000 Write/Erase Cycles

•

512 bytes Internal SRAM

•

32 x 8 General Purpose Working Registers

•

32 Programmable I/O Lines

•

Programmable Serial UART

•

SPI Serial Interface

•

VCC: 2.7 - 6.0V

•

Fully Static Operation

– 0 - 8 MHz 4.0 - 6.0V,
– 0 - 4 MHz 2.7 - 4.0V

•

Up to 8 MIPS Throughput at 8 MHz

•

One 8-Bit Timer/Counter with Separate Prescaler

•

One 16-Bit Timer/Counter with Separate Prescaler
and Compare and Capture Modes

•

Dual PWM

•

External and Internal Interrupt Sources

•

Programmable Watchdog Timer with On-Chip Oscillator

•

On-Chip Analog Comparator

•

Low Power Idle and Power Down Modes

•

Programming Lock for Software Security

8-Bit
Microcontr oller
with 8K bytes
In-System
Programmable
Flash

AT90S8515

Description

The AT90S8 515 is a low-p ower CMOS 8-bit mic rocontroll er based on the AVR
enhanced RISC architecture . By exe cuting powe rful instruc tions in a single clock
cycle, the AT90S8515 achieves throughpu ts approaching 1 MIPS per MHz allowing
the system designer to optimize power consumption versus processing speed.

The AVR core combines a rich instr uction set with 32 gene ral purpose working regis­ters. All the 32 registers are directly connected to the Arithmetic Logic Unit (ALU),
allowing two indep endent r egisters to be acce ssed in one singl e instr uction execute d
in one clock cycle. Th e resulting arc hitecture is mor e code efficie nt while achievin g
throughputs up to ten times faster than conventional CISC microcontrollers.

(continued)

Pin Configurations

Preliminary

®

Rev. 0841DS–06/98

Note: This is a sumary document. For the complete
76 page document, please visit our Web site at

www.atmel.com

and request literature number 0841D.

or e-mail at

[e-mail]

1

Block Diagram

Figure 1.

The AT90S8515 Block Diagram

The AT90S8515 provides the following features: 8K bytes
of In-System Programmable Flash, 512 bytes EEPROM,
512 bytes SRAM, 32 gen eral purpo se I/O li nes, 3 2 general
purpose working registers, flexible timer/counters with
compare modes, internal and external interrupts, a pro­grammable serial UART, programmable Watchdog Timer
with internal oscillator, an SPI serial port and two software
selectable pow er saving modes. T he Idl e Mode sto ps the
CPU while allowing the SRAM, timer/counters, SPI port
and interrupt syste m to contin ue functioning . The power
down mode saves the register contents but freezes the
oscillator, disabling all other chip functions until the next
interrupt or hardware reset.

2

AT90S8515

The device is manufac tured using Atmel’ s high density
non-volatile memory technology. The on-chip in-system
programmable Flash allows the program memory to be
reprogrammed in-sys tem th ro ugh an S PI se rial i nterface or
by a conventional n onvolatile memo ry programmer. By
combining an enhanced RISC 8-bit CPU wit h In-System
Programmable Flash on a monolithic chip, the Atmel
AT90S8515 is a powerful microcontroller that provides a
highly flexible and co st effect ive solution to many em bed­ded control applications.

The AT90S8515 AVR is supported with a full s uite of pro­gram and system development tools including: C compil­ers, macro assemblers, program debugger/si mulators, in­circuit emulators, and evaluati on kits.

AT90S8515

Pin Descriptions

V

CC

Supply voltage

GND

Ground

Port A (PA7..PA0)

Port A is an 8 -bit b idirec tional I/O port. Port p ins ca n pro­vide internal pull-up resistors (selected for each bit). The
Port A output buffers can sink 20mA and can drive LED dis­plays directly. When pins PA0 to PA7 are used as inputs
and are externally pull ed low, they will source c urrent if the
internal pull-up resistors are activated.

Port A serves as Multiplexed Address/Data input/output
when using external SRAM.

Port B (PB7..PB0)

Port B is an 8-bit bidirectional I/O pins with internal pull-up
resistors. The Port B output buffers can sink 20 mA. As
inputs, Port B pins t hat a re ex ter nally pu ll ed l ow wi ll sour c e
current if the pull-up resistors are activated.

Port B also serves the fu nction s of vario us speci al feat ures
of the AT90S8515 as listed on page 46.

Port C (PC7..PC0)

Port C is an 8-bit bidirectional I/O port with internal pull-up
resistors. The Port C output buffers can sink 20 mA. As
inputs, Port C pins that are exter nal ly pul led low wil l sour ce
current if the pull-up resistors are activated.

Port C als o s erv es as Addr es s ou tp ut when us ing ext ern al
SRAM.

Port D (PD7..PD0)

Port D is an 8-bit bidirectional I/O port with internal pull-up
resistors. The Port D output buffers can sink 20 mA. As
inputs, Port D pins that are exter nal ly pul led low wil l sour ce
current if the pull-up resistors are activated.

Port D also serves th e fu nc tion s of v ario us sp ec ial fea tur es
of the AT90S8515 as listed on page 52.

RESET

Reset input. A low on th is pi n for two machi ne cy cles wh ile
the oscillator is running resets the device.

XTAL1

Input to the inverting os cillator amplifi er and input to th e
internal clock operating circuit.

XTAL2

Output from the inverting oscillator amplifier

ICP

ICP is the input pin for the Time r/Counter1 Inpu t Capture
function.

OC1B

OC1B is the output pin for the Timer/Counter1 Output
CompareB function

ALE

ALE is the Address Latch Enable used when the Ex ternal
Memory is enabled. The ALE strob e is used to latch the
low-order address (8 bits) into an address latch during the
first access cy cle, and the A D0-7 pins a re used for data
during the second access cycle.

Crystal Oscillator

XTAL1 and XTAL2 are input and output, respectively, of an
inverting amplifier which can be configured for use as an
on-chip oscillator, as shown in Figure 2. Either a quartz
crystal or a ceramic resonator may be used. To drive the
device from an external clock source, XTAL2 should be left
unconnected while XTAL1 is driven as shown in Figure 3.

Figure 2.

Figure 3.

Oscillator Connec tio ns

External Clock Drive Configuration

3

AT90S8515 Architectural Overview

The fast-access register file concept contains 32 x 8-bit
general purpose worki ng regi ster s with a sin gle cl ock c ycle
access time. This means that during one single clock cycle,
one ALU (Arithmetic Logic Unit) operation is executed. Two
operands are output from the register file, the operation is
executed, and the result is stored back in the register file ­in one clock cycle.

Six of the 32 registers can be used as three 16-bits indirect
address register pointers for Data Space addressing ­enabling efficient address calculati ons. One of the three
address pointers is also used as the address pointer for the
constant table look up function. These added function reg­isters are the 16-bits X-register, Y-register and Z-register.

Figure 4.

The AT90S8515

AVR

Enhanced RISC Architecture

The ALU supports arithmetic and logic functions between
registers or be tween a const ant and a r egist er. Si ngle re g­ister operations are also executed in the ALU. Figure 4
shows the AT90S851 5 AVR Enhan ced RISC mi crocontro l­ler architecture .

In addition to the register operation, the conventional mem­ory addressing mode s can be used on the re gister file as
well. This is e nabled by th e fact that t he register f ile is
assigned the 32 lowermost Data Space addresses ($00 ­$1F), allowing them to be accessed as though they were
ordinary memory locations.

The I/O memory space contains 64 addresses for CPU
peripheral functions as Control Registers, Timer/Counters,
A/D-converte rs, and ot her I/O fun ctions. T he I/O Mem ory
can be accessed dir ectly, or as the Da ta Space loca tions
following those of the register file, $20 - $5F.

4

AT90S8515

AVR

The
rate memories and buses fo r program and data. The pr o­gram memory is executed with a two stage pipeline. While
one instruction is bein g executed, the next ins truction is
pre-fetched from the program memory. This co ncept
enables instructions to be executed in every clock cycle.
The program memory is in-system programmable Flash
memory.

With the relat ive jump an d call i nstructi ons, the w hole 4K
address space i s directl y access ed. Most AVR in struc tions
have a single 16-bit word format. Every program memory
address contains a 16- or 32-bit instruction.

During interrupts and su broutine calls, t he retur n addre ss
program counter (PC) is stor ed on the stack. The stack is
effectively allo cated i n the gene ral dat a SRAM, and cons e­quently the stack size is only limited by the total SRAM size
and the usage of the SR AM. All user progr ams must initial-

uses a Harvard architecture concept - with sepa-

AT90S8515

ize the SP in the reset routine (before subroutines or inter­rupts are execute d). The 16-bit stack pointer SP is
read/write accessib le in the I/O spac e.

The 512 bytes data SRAM can be easily access ed through
the five different addressing modes supported in th e AVR
architecture.

The memory spaces in the AVR
and regular memory maps.

A flexible interrupt module has its control registers in the
I/O space with an additional global interrupt enable bit in
the status register. All the different interrupts have a sepa­rate interrupt vector in the interrupt vector table at the
beginning of the program memory. The different interrupts
have priority in accordance with their interrupt vector posi­tion. The lower the interrupt vector address the higher the
priority.

architecture are all linear

Figure 5.

Memory Maps

5

AT90S8515 Register Summary

Address Name Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 Page

$3F ($5F) SREG I T H S V N Z C 18
$3E ($5E) SPH SP15 SP14 SP13 SP12 SP11 SP10 SP9 SP8 19
$3D ($5D) SPL SP7 SP6 SP5 SP4 SP3 SP2 SP1 SP0 19
$3C ($5C) Reserved
$3B ($5B) GIMSK INT1 INT0 - - - - - -24
$3A ($5A) GIFR INTF1 INTF0

$39 ($59) TIMSK TOIE1 OCIE1A OCIE1B
$38 ($58) TIFR TOV1 OCF1A OCF1B
$37 ($57) Reserved
$36 ($56) Reserved
$35 ($55) MCUCR SRE SRW SE SM ISC11 ISC10 ISC01 ISC00 26
$34 ($54) Reserved
$33 ($53) TCCR0 - - - - - CS02 CS01 CS00 29
$32 ($52) TCNT0 Timer/Counter0 (8 Bit) 30
$31 ($51) Reserved

$30 ($50) Reserved
$2F ($4F) TCCR1A COM1A1 COM1A0 COM1B1 COM1B0 - -PWM11PWM10 32
$2E ($4E) TCCR1B ICNC1 ICES1
$2D ($4D) TCNT1H Timer/Counter1 - Counter Register High Byte 34
$2C ($4C) TCNT1L Timer/Counter1 - Counter Regi st er Low Byt e 34
$2B ($4B) OCR1AH Timer/Counter1 - Output Compare Register A High Byte 35
$2A ($4A) OCR1AL Timer/Counter1 - Output Compare Register A Low Byte 35

$29 ($49) OCR1BH Timer/Counter1 - Output Compare Register B High Byte 35

$28 ($48) OCR1BL Timer/Counter1 - Output Compare Register B Low Byte 35

$27 ($47) Reserved

$26 ($46) Reserved

$25 ($45) ICR1H Timer/Counter1 - Input Capture Register High Byte 36

$24 ($44) ICR1L Timer/Counter1 - Input Capture Register Low Byte 36

$23 ($43) Reserved

$22 ($42) Reserved

$21 ($41) WDTCR - - - WDTOE WDE WDP2 WDP1 WDP0 38

$20 ($40) Reserved
$1F ($3F) Reserved - - - - - - - EEAR8 39
$1E ($3E) EEARL EEPROM Address Register Low Byte 39
$1D ($3D) EEDR EEPROM Data Register 39
$1C ($3C) EECR
$1B ($3B) PORTA PORTA7 PORTA6 PORTA5 PORTA4 PORTA3 PO RTA2 PORTA1 PORTA0 54
$1A ($3A) DDRA DDA7 DDA6 DDA5 DDA4 DDA3 DDA2 DDA1 DDA0 54

$19 ($39) PINA PINA7 PINA6 PINA5 PINA4 PINA3 PINA2 PINA1 PINA0 54

$18 ($38) PORTB PORTB7 PORTB6 PORTB5 PORTB4 PORTB3 PO RTB2 PORTB1 PORTB0 56

$17 ($37) DDRB DDB7 DDB6 DDB5 DDB4 DDB3 DDB2 DDB1 DDB0 56

$16 ($36) PINB PINB7 PINB6 PINB5 PINB4 PINB3 PINB2 PINB1 PINB0 56

$15 ($35) PORTC PORTC7 PORTC6 PORTC5 PORTC4 PORTC3 PORTC2 PORTC1 PORTC0 61

$14 ($34) DDRC DDC7 DDC6 DDC5 DDC4 DDC3 DDC2 DDC1 DDC0 61

$13 ($33) PINC PINC7 PINC6 PINC5 PINC4 PINC3 PINC2 PINC1 PINC0 61

$12 ($32) PORTD PORTD7 PORTD6 PORTD5 PORTD4 PORTD3 PORTD2 PORTD1 PORTD0 63

$11 ($31) DDRD DDD7 DDD6 DDD5 DDD4 DDD3 DDD2 DDD1 DDD0 63

$10 ($30) PIND PIND7 PIND6 PIND5 PIND4 PIND3 PIND2 PIND1 PIND0 63
$0F ($2F) SPDR SPI Data Register 45
$0E ($2E) SPSR SP IF WCOL
$0D ($2D) SPCR SPIE SPE DORD MSTR CPOL CPHA SPR1 SPR0 44
$0C ($2C) UDR UART I/O Data Register 48
$0B ($2B) USR RXC TXC UDRE FE OR
$0A ($2A) UCR RXCIE TXCIE UDRIE RXEN TXEN CHR9 RXB8 TXB8 49

$09 ($29) UBRR UART Baud Rate Register 51

$08 ($28) ACSR ACD

… Reserved

$00 ($20) Reserved

- - - - - EEMWE EEWE EERE 40

- ACO ACI ACIE ACI C ACIS1 ACIS0 52

- - CTC1 CS12 CS11 CS10 33

- - - - - -44

- TICIE1 - TOIE0 -24

-ICF1-TOV0 -25

- - -48

24

6

AT90S8515

AT90S8515

AT90S8515 Instruction Set Summary

Mnemonics Operands Description Operation Flags #Clocks

ARITHMETIC AND LOGIC INSTRUCTIONS

ADD Rd, Rr Add two Registers Rd ← Rd + Rr Z,C,N,V,H 1
ADC Rd, Rr Add with Carry two Registers Rd ← Rd + Rr + C Z,C,N,V,H 1
ADIW Rdl,K Add Immediate to Word Rdh:Rdl ← Rdh:Rdl + K Z,C,N,V,S 2
SUB Rd, Rr Subtract two Registers Rd ← Rd - Rr Z,C,N,V,H 1
SUBI Rd, K Subtract Constant from Register Rd ← Rd - K Z,C,N,V,H 1
SBC Rd, Rr Subtract with Carry two Registers Rd ← Rd - Rr - C Z,C,N,V,H 1
SBCI Rd, K Subtract with Carry Constant from Reg. Rd ← Rd - K - C Z,C,N,V,H 1
SBIW Rdl,K Subtract Immediate from Word Rdh:Rdl ← Rdh:Rdl - K Z,C,N,V,S 2
AND Rd, Rr Logical AND Registers Rd ← Rd • Rr Z,N,V 1
ANDI Rd, K Logical AND Register and Constant Rd ← Rd • K Z,N,V 1
OR Rd, Rr Logical OR Registers Rd ← Rd v Rr Z,N,V 1
ORI Rd, K Logical OR Register and Constant Rd ← Rd v K Z,N,V 1
EOR Rd, Rr Exclusive OR Registers Rd ← Rd ⊕ Rr Z,N,V 1
COM Rd One’s Complement Rd ← $FF − Rd Z,C,N,V 1
NEG Rd Two’s Complement Rd ← $00 − Rd Z,C,N,V,H 1
SBR Rd,K Set Bit(s) in Register Rd ← Rd v K Z,N,V 1
CBR Rd,K Clear Bit(s) in Register Rd ← Rd • ($FF - K) Z,N,V 1
INC Rd Increment Rd ← Rd + 1 Z,N,V 1
DEC Rd Decrement Rd ← Rd − 1 Z,N,V 1
TST Rd Test for Zero or Minus Rd ← Rd • Rd Z,N,V 1
CLR Rd Clear Register Rd ← Rd ⊕ Rd Z,N,V 1
SER Rd Set Register Rd ← $FF None 1

BRANCH INSTRUCTIONS

RJMP k Relative Jump PC ← PC + k + 1 None 2
IJMP Indirect Jump to (Z) PC ← Z None 2
RCALL k Relative Subroutine Call PC ← PC + k + 1 None 3
ICALL Indirect Call to (Z) PC ← ZNone3
RET Subroutine Return PC ← ST A C K None 4
RETI Interrupt Return PC ← STACK I 4
CPSE Rd,Rr Compare, Skip if Equal if (Rd = Rr) PC ← PC + 2 or 3 None 1 / 2
CP Rd,Rr Compare Rd − Rr Z, N,V,C,H 1
CPC Rd,Rr Compare with Carry Rd − Rr − C Z, N,V,C,H 1
CPI Rd,K Compare Register with Immediate Rd − K Z, N,V,C,H 1
SBRC Rr, b Skip if Bit in Register Cleared if (Rr(b)=0) PC ← PC + 2 or 3 None 1 / 2
SBRS Rr, b Skip if Bit in Register is Set if (Rr(b)=1) PC ← PC + 2 or 3 None 1 / 2
SBIC P, b Skip if Bit in I/O Register Cleared if (P(b)=0) PC ← PC + 2 or 3 None 1 / 2
SBIS P, b Skip if Bit in I/O Register is Set if (P(b)=1) PC ← PC + 2 or 3 None 1 / 2
BRBS s, k Branch if Status Flag Set if (SREG(s) = 1) then PC←PC+k + 1 None 1 / 2
BRBC s, k Branch if Status Flag Cleared if (SREG(s) = 0) then PC←PC+k + 1 None 1 / 2
BREQ k Branch if Equal if (Z = 1) then PC ← PC + k + 1 None 1 / 2
BRNE k Branch if Not Equal if (Z = 0) then PC ← PC + k + 1 None 1 / 2
BRCS k Branch if Carry Set if (C = 1) then PC ← PC + k + 1 None 1 / 2
BRCC k Branch if Carry Cleared if (C = 0) then PC ← PC + k + 1 None 1 / 2
BRSH k Branch if Same or Higher if (C = 0) then PC ← PC + k + 1 None 1 / 2
BRLO k Branch if Lower if (C = 1) then PC ← PC + k + 1 None 1 / 2
BRMI k Branch if Minus if (N = 1) then PC ← PC + k + 1 None 1 / 2
BRPL k Branch if Plus if (N = 0) then PC ← PC + k + 1 None 1 / 2
BRGE k Branch if Greater or Equal, Signed if (N ⊕ V= 0) then PC ← PC + k + 1 None 1 / 2
BRLT k Branch if Less Than Zero, Signed if (N ⊕ V= 1) then PC ← PC + k + 1 None 1 / 2
BRHS k Branch if Half Carry Flag Set if (H = 1) then PC ← PC + k + 1 None 1 / 2
BRHC k Branch if Half Carry Flag Cleared if (H = 0) then PC ← PC + k + 1 None 1 / 2
BRTS k Branch if T Flag Set if (T = 1) then PC ← PC + k + 1 None 1 / 2
BRTC k Branch if T Flag Cleared if (T = 0) then PC ← PC + k + 1 None 1 / 2
BRVS k Branch if Overflow Flag is Set if (V = 1) then PC ← PC + k + 1 None 1 / 2
BRVC k Branch if Overflow Flag is Cleared if (V = 0) then PC ← PC + k + 1 None 1 / 2
BRIE k Branch if Interrupt Enabled if ( I = 1) then PC ← PC + k + 1 None 1 / 2
BRID k Branch if Interrupt Disabled if ( I = 0) then PC ← PC + k + 1 None 1 / 2

7

AT90S8515 Instruction Set Summary

Mnemonics Operands Description Operation Flags #Clocks

DATA TRANSFER INSTRUCTIONS

MOV Rd, Rr Move Bet ween Regi ster s Rd ← Rr None 1
LDI Rd, K Load Imm edia te Rd ← KNone1
LD Rd, X Load Indirect Rd ← (X) None 2
LD Rd, X+ Load Indirect and Post-Inc. Rd ← (X), X ← X + 1 None 2
LD Rd, - X Load Indirect and Pre-Dec. X ← X - 1, Rd ← (X) None 2
LD Rd, Y Load Indirect Rd ← (Y) None 2
LD Rd, Y+ Load Indirect and Post-Inc. Rd ← (Y), Y ← Y + 1 None 2
LD Rd, - Y Load Indirect and Pre-Dec. Y ← Y - 1, Rd ← (Y) None 2
LDD Rd,Y+q Load Indirect with Displacement Rd ← (Y + q) None 2
LD Rd, Z Load Indirect Rd ← (Z) None 2
LD Rd, Z+ Load Indirect and Post-Inc. Rd ← (Z), Z ← Z+1 None 2
LD Rd, -Z Load Indirect and Pre-Dec. Z ← Z - 1, Rd ← (Z) None 2
LDD Rd, Z+q Loa d Indi r ect wit h Disp lace men t Rd ← (Z + q) None 2
LDS Rd, k Load Direct from SRAM Rd ← (k) None 2
ST X, Rr Store Indirect (X) ← Rr None 2
ST X+, Rr Store Indirect and Post-Inc. (X) ← Rr, X ← X + 1 None 2
ST - X, Rr Store Indirect and Pre-Dec. X ← X - 1, (X) ← Rr None 2
ST Y, Rr Store Indirect (Y) ← Rr None 2
ST Y+, Rr Store Indirect and Post-Inc. (Y) ← Rr, Y ← Y + 1 None 2
ST - Y, Rr Store Indirect and Pre-Dec. Y ← Y - 1, (Y) ← Rr None 2
STD Y+q,Rr Store Indirect with Displacement (Y + q) ← Rr None 2
ST Z, Rr Store Indirect (Z) ← Rr None 2
ST Z+, Rr Store Indirect and Post-Inc. (Z) ← Rr, Z ← Z + 1 None 2
ST -Z, Rr Store Indirect and Pre-Dec. Z ← Z - 1, (Z) ← Rr None 2
STD Z+q,Rr Store Indirect with Displacement (Z + q) ← Rr None 2
STS k, Rr Store Direct to SRAM (k) ← Rr None 2
LPM Load Program Memory R0 ← (Z) None 3
IN Rd, P In Port Rd ← PNone1
OUT P, Rr Out Port P ← Rr None 1
PUSH R r Pu sh Regi st er on St ack STACK ← Rr None 2
POP Rd Pop Register from Stack Rd ← STACK None 2

BIT AND BIT-TEST INSTRUCTIONS

SBI P,b Set Bit in I/O Register I/O(P,b) ← 1None2
CBI P,b Clear Bit in I/O Register I/O(P,b) ← 0None2
LSL Rd Logical Shift Left Rd(n+1) ← Rd(n), Rd(0) ← 0 Z,C,N,V 1
LSR Rd Logical Shift Right Rd(n) ← Rd(n+1), Rd(7) ← 0 Z,C,N,V 1
ROL Rd Rotate Left Through Carry Rd(0)←C,Rd(n+1)← Rd(n),C←Rd(7) Z,C,N,V 1
ROR Rd Rotate Right Through Carry Rd(7)←C,Rd(n)← Rd(n+1),C←Rd(0) Z,C,N,V 1
ASR Rd Arithmetic Shift Right Rd(n) ← Rd(n+1), n=0..6 Z,C,N,V 1
SWAP Rd Swap Nibbles Rd(3..0)←Rd(7..4),Rd(7..4)←Rd(3..0) None 1
BSET s Flag Set SREG(s) ← 1 SREG(s) 1
BCLR s Flag Clear SREG(s) ← 0 SREG(s) 1
BST Rr, b Bit Store from Register to T T ← Rr(b) T 1
BLD Rd, b Bit load from T to Register Rd(b) ← TNone1
SEC Set Carry C ← 1C1
CLC Clear Carry C ← 0 C 1
SEN Set Negative Flag N ← 1N1
CLN Clear Negative Flag N ← 0 N 1
SEZ Set Zero Flag Z ← 1Z1
CLZ Clear Zero Flag Z ← 0 Z 1
SEI Global Interrupt Enable I ← 1I1
CLI Global Interrupt Disable I ← 0 I 1
SES Set Signed Test Flag S ← 1S1
CLS Clear Signed Test Flag S ← 0 S 1
SEV Set Twos Complement Overflow. V ← 1V1
CLV Clear Twos Complement Overflow V ← 0 V 1
SET Set T in SREG T ← 1T1
CLT Clear T in SREG T ← 0 T 1
SEH Set Half Carry Flag in SREG H ← 1H1
CLH Clear Half Carry Flag in SREG H ← 0 H 1
NOP No Operation None 1
SLEEP Sleep (see specific descr. for Sleep function) None 3
WDR Watchdog Reset (see specific descr. for WDR/timer) None 1

8

AT90S8515