AT91RM9200-CI-002 Atmel, AT91RM9200-CI-002 Datasheet - Page 207

• Manufacturer Part Number: AT91RM9200-CI-002
• Description: IC ARM9 MCU 256 BGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91RM9200-CI-002

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 180MHz
• Connectivity: EBI/EMI, Ethernet, I²C, MMC, SPI, SSC, UART/USART, USB
• Peripherals: POR
• Number Of I /o: 122
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: ROM
• Ram Size: 48K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 256-BGA
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Data Converters: -

19.7.2
Register Name:
Access Type:
Reset Value:
• COUNT: SDRAMC Refresh Timer Count
This 12-bit field is loaded into a timer that generates the refresh pulse. Each time the refresh pulse is generated, a refresh
burst is initiated. The value to be loaded depends on the SDRAMC clock frequency (MCK: Master Clock), the refresh rate
of the SDRAM device and the refresh burst length where 15.6 µs per row is a typical value for a burst of length one.
To refresh the SDRAM device even if the reset value is not equal to 0, this 12-bit field must be written. If this condition is not
satisfied, no refresh command is issued and no refresh of the SDRAM device is carried out.
1768I–ATARM–09-Jul-09
31
23
15
–
–
–
7
SDRAMC Refresh Timer Register
30
22
14
SDRAMC_TR
Read/Write
0x00000800
–
–
–
6
29
21
13
–
–
–
5
28
20
12
–
–
–
4
COUNT
27
19
11
–
–
3
26
18
10
–
–
2
COUNT
AT91RM9200
25
17
–
–
9
1
24
16
–
–
8
0
207