AT91SAM9G45-CU-999 Atmel, AT91SAM9G45-CU-999 Datasheet - Page 266

• Manufacturer Part Number: AT91SAM9G45-CU-999
• Description: IC MCU ARM9 APMC 324TFBGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM9G45-CU-999

• Core Processor: ARM9
• Core Size: 16/32-Bit
• Speed: 400MHz
• Connectivity: EBI/EMI, Ethernet, I²C, IrDA, MMC, SPI, SSC, UART/USART, USB
• Peripherals: AC'97, DMA, I²S, LCD, POR, PWM, WDT
• Number Of I /o: 160
• Program Memory Size: 64KB (64K x 8)
• Program Memory Type: ROM
• Ram Size: 128K x 8
• Voltage - Supply (vcc/vdd): 0.9 V ~ 1.1 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 324-TFBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Supplier Unconfirmed

• TWTR: Internal Write to Read Delay
Reset value is 0.
This field defines the internal write to read command Time in number of cycles. Number of cycles is between 1 and 7.
In the case of low-power DDR-SDRAM device only bit 24 (TWTR[0]) is used. Bit [26:25] must be set to 0.
• REDUCE_WRRD: Reduce Write to Read Delay
Reset value is 0.
This field reduces the delay between write to read access for low-power DDR-SDRAM devices with a latency equal to 2. To
use this feature, TWTR field must be equal to 0. Important to note is that some devices do not support this feature.
• TMRD: Load Mode Register Command to Active or Refresh Command
Reset Value is 2 cycles.
This field defines the delay between a Load mode register command and an active or refresh command in number of
cycles. Number of cycles is between 0 and 15.
266
Bit 24 (twtr[0])
AT91SAM9G45
0
1
Twtr value
1
2
6438F–ATARM–21-Jun-10