AT91SAM7SE256B-CUR Atmel, AT91SAM7SE256B-CUR Datasheet - Page 211

• Manufacturer Part Number: AT91SAM7SE256B-CUR
• Description: IC ARM7 MCU FLASH 256K 128-LQFP
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7SE256B-CUR

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: EBI/EMI, I²C, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 88
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Processor Series: SAM7SE256
• Core: ARM7TDMI
• Data Bus Width: 32 bit
• Data Ram Size: 32 KB
• Interface Type: SPI, USB
• Maximum Clock Frequency: 48 MHz
• Number Of Programmable I/os: 88
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Operating Temperature Range: - 40 C to + 85 C
• Processor To Be Evaluated: AT91SAM7SE256B
• Supply Current (max): 60 uA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

23.7.1
Name:
Access:
Reset Value:
• MODE: SDRAMC Command Mode
This field defines the command issued by the SDRAM Controller when the SDRAM device is accessed.
• DBW: Data Bus Width
0: Data bus width is 32 bits.
1: Data bus width is 16 bits.
6222F–ATARM–14-Jan-11
0
0
0
0
0
31
23
15
–
–
–
7
–
0
0
0
0
1
MODE
SDRAMC Mode Register
0
0
1
1
0
0
1
0
1
0
30
22
14
SDRAMC_MR
Read/Write
0x00000010
–
–
–
6
–
Description
Normal mode. Any access to the SDRAM is decoded normally.
The SDRAM Controller issues a NOP command when the SDRAM device is accessed regardless of the
cycle.
The SDRAM Controller issues an “All Banks Precharge” command when the SDRAM device is accessed
regardless of the cycle.
The SDRAM Controller issues a “Load Mode Register” command when the SDRAM device is accessed
regardless of the cycle. The address offset with respect to the SDRAM device base address is used to
program the Mode Register. For instance, when this mode is activated, an access to the “SDRAM_Base +
offset” address generates a “Load Mode Register” command with the value “offset” written to the SDRAM
device Mode Register.
The SDRAM Controller issues a “Refresh” Command when the SDRAM device is accessed regardless of
the cycle. Previously, an “All Banks Precharge” command must be issued.
29
21
13
–
–
–
5
–
DBW
28
20
12
–
–
–
4
SAM7SE512/256/32 Preliminary
27
19
11
–
–
–
3
26
18
10
–
–
–
2
MODE
25
17
–
–
9
–
1
24
16
–
–
8
–
0
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