AT90S8515A-8PC Atmel, AT90S8515A-8PC Datasheet - Page 3

• Manufacturer Part Number: AT90S8515A-8PC
• Description: IC MCU 8K FLSH 8MHZ 40DIP
• Manufacturer: Atmel
• Series: AVR® 90Sr

Specifications of AT90S8515A-8PC

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 32
• Program Memory Size: 8KB (4K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 512 x 8
• Ram Size: 512 x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 6 V
• Oscillator Type: Internal
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 40-DIP (0.600", 15.24mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Data Converters: -

1. Skip Instruction with Interrupts
1195E–09/01
A skip instruction (SBRS, SBRC, SBIS, SBIC, CPSE) that skips a 2-word instruction needs 3 clock cycles. If an inter-
rupt occurs during the first or second clock cycle of this skip instruction, the return address will not be stored correctly
on the stack. In this situation, the address of the second word in the 2-word instruction is stored. This means that on
return from interrupt, the second word of the 2-word command will be decoded and executed as an instruction. The
AT90S8515 has two 2-word instructions: LDS and STS.
Note 1: This can only occur if all of the following conditions are true:
- A skip instruction is followed by a 2-word instruction.
- The skip instruction is actually skipping the 2-word instruction.
- Interrupts are enabled, and at least one interrupt source can generate an interrupt.
- An interrupt arrives in the first or second cycle of the skip instruction.
Note 2: This will cause problems only if the address of the following LDS or STS command points to an address
beyond 400 Hex.
Problem Fix/Workaround
For assembly program, avoid skipping a 2-word instruction if interrupts are enabled.
The following C-compilers handle this sequence correctly:
- IAR Compiler, version 1.40b or later
- Image Craft Compiler, all versions
- Codevision Compiler, version 1.0.0.5 or later
AT90S8515 Errata
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