AT90S8515-8PC Atmel, AT90S8515-8PC Datasheet - Page 61

• Manufacturer Part Number: AT90S8515-8PC
• Description: IC MCU 8K FLSH 8MHZ 40DIP
• Manufacturer: Atmel
• Series: AVR® 90Sr

Specifications of AT90S8515-8PC

• 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: -

0841G–09/01
Default, the external SRAM access, is a 3-cycle scheme as depicted in Figure 43. When
one extra wait state is needed in the access cycle, set the SRW bit (one) in the MCUCR
register. The resulting access scheme is shown in Figure 44. In both cases, note that
PORTA is data bus in one cycle only. As soon as the data access finishes, PORTA
becomes a low-order address bus again.
For details of the timing for the SRAM interface, please refer to Figure 68, Table 37,
Table 38, Table 39 and Table 40, beginning on page 92. Refer to “Architectural Over-
view” on page 7 for a description of the memory map, including address space for
SRAM.
Figure 42. External SRAM Connected to the AVR
Figure 43. External Data SRAM Memory Cycles without Wait State
Data/Address [7..0]
Data/Address [7..0]
System Clock Ø
Address [15..8]
AVR
Port C
Port A
ALE
WR
RD
ALE
WR
RD
Prev. Address
Prev. Address
Prev. Address
T1
Address
Address
D
G
T2
Q
Data
Address
Data
T3
AT90S8515
D[7:0]
A[15:8]
A[7:0]
RD
WR
Address
Address
SRAM
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