ATMEGA8515-16AI Atmel, ATMEGA8515-16AI Datasheet - Page 29

• Manufacturer Part Number: ATMEGA8515-16AI
• Description: IC AVR MCU 8K 16MHZ IND 44-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA8515-16AI

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 35
• 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): 4.5 V ~ 5.5 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Data Converters: -

XMEM Register
Description
MCU Control Register –
MCUCR
Extended MCU Control
Register – EMCUCR
2512K–AVR–01/10
Figure 16. External Data Memory Cycles with SRWn1 = 1 and SRWn0 = 1
Note:
• Bit 7 – SRE: External SRAM/XMEM Enable
Writing SRE to one enables the External Memory Interface.The pin functions AD7:0,
A15:8, ALE, WR, and RD are activated as the alternate pin functions. The SRE bit over-
rides any pin direction settings in the respective Data Direction Registers. Writing SRE
to zero, disables the External Memory Interface and the normal pin and data direction
settings are used.
• Bit 6 – SRW10: Wait State Select Bit
For a detailed description, see common description for the SRWn bits below (EMCUCR
description).
• Bit 6..4 – SRL2, SRL1, SRL0: Wait State Sector Limit
It is possible to configure different wait states for different external memory addresses.
The External Memory address space can be divided in two sectors that have separate
wait state bits. The SRL2, SRL1, and SRL0 bits select the splitting of these sectors, see
Table 2 and Figure 11. By default, the SRL2, SRL1, and SRL0 bits are set to zero and
the entire External Memory address space is treated as one sector. When the entire
System Clock (CLK
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
DA7:0 (XMBK = 0)
DA7:0 (XMBK = 1)
1. SRWn1 = SRW11 (upper sector) or SRW01 (lower sector), SRWn0 = SRW10 (upper
DA7:0
A15:8
CPU
ALE
WR
RD
sector) or SRW00 (lower sector)
The ALE pulse in period T7 is only present if the next instruction accesses the RAM
(internal or external).
)
Prev. Addr.
Prev. Data
Prev. Data
Prev. Data
SRE
R/W
SM0
R/W
7
0
7
0
T1
SRW10
SRL2
R/W
R/W
6
0
6
0
Address
Address
Address
T2
SRL1
R/W
R/W
SE
XX
5
0
5
0
Address
T3
SRL0
SM1
R/W
R/W
Data
Data
Data
4
0
4
0
SRW01
ISC11
R/W
R/W
T4
3
0
3
0
SRW00
ISC10
R/W
R/W
2
0
2
0
ATmega8515(L)
T5
SRW11
ISC01
R/W
R/W
1
0
1
0
T6
ISC00
ISC2
R/W
R/W
0
0
0
0
(1)
T7
EMCUCR
MCUCR
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