ATMEGA128A-ANR Atmel, ATMEGA128A-ANR Datasheet - Page 34

• Manufacturer Part Number: ATMEGA128A-ANR
• Description: IC MCU AVR 128K FLASH 64TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA128A-ANR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: EBI/EMI, I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 53
• Program Memory Size: 128KB (64K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 4K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP
• Core: AVR8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.6.5
8151H–AVR–02/11
XMCRA - External Memory Control Register A
to one enables the wait-state and one extra cycle is added during read/write strobe as shown in
Figure
• Bit 7 – Res: Reserved Bit
This is a reserved bit and will always read as zero. When writing to this address location, write
this bit to zero for compatibility with future devices.
• 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 split of the sectors, see
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 SRAM address space is configured as one sec-
tor, the wait-states are configured by the SRW11 and SRW10 bits.
Table 7-3.
• Bit 1 and Bit 6 MCUCR – SRW11, SRW10: Wait-state Select Bits for Upper Sector
The SRW11 and SRW10 bits control the number of wait-states for the upper sector of the exter-
nal memory address space, see
• Bit 3:2 – SRW01, SRW00: Wait-state Select Bits for Lower Sector
The SRW01 and SRW00 bits control the number of wait-states for the lower sector of the exter-
nal memory address space, see
Bit
Read/Write
Initial Value
SRL2
0
0
0
0
1
1
1
1
7-7.
Sector limits with different settings of SRL2:0
R
7
–
0
SRL1
0
0
1
1
0
0
1
1
SRL2
R/W
6
0
SRL0
Table
Table
0
1
0
1
0
1
0
1
SRL1
R/W
5
0
7-4.
7-4.
Sector Limits
Lower sector = N/A
Upper sector = 0x1100 - 0xFFFF
Lower sector = 0x1100 - 0x1FFF
Upper sector = 0x2000 - 0xFFFF
Lower sector = 0x1100 - 0x3FFF
Upper sector = 0x4000 - 0xFFFF
Lower sector = 0x1100 - 0x5FFF
Upper sector = 0x6000 - 0xFFFF
Lower sector = 0x1100 - 0x7FFF
Upper sector = 0x8000 - 0xFFFF
Lower sector = 0x1100 - 0x9FFF
Upper sector = 0xA000 - 0xFFFF
Lower sector = 0x1100 - 0xBFFF
Upper sector = 0xC000 - 0xFFFF
Lower sector = 0x1100 - 0xDFFF
Upper sector = 0xE000 - 0xFFFF
SRL0
R/W
4
0
SRW01
R/W
3
0
SRW00
R/W
2
0
Table 7-3
SRW11
ATmega128A
R/W
1
0
and
R
0
–
0
Figure
XMCRA
7-4. By
34