at91sam9g20-cu ATMEL Corporation, at91sam9g20-cu Datasheet - Page 215

• Manufacturer Part Number: at91sam9g20-cu
• Description: At91 Arm Thumb Microcontrollers
• Manufacturer: ATMEL Corporation

• CAS: CAS Latency
Reset value is two cycles.
In the SDRAMC, only a CAS latency of one, two and three cycles are managed.
• DBW: Data Bus Width
Reset value is 16 bits
0: Data bus width is 32 bits.
1: Data bus width is 16 bits.
• TWR: Write Recovery Delay
Reset value is two cycles.
This field defines the Write Recovery Time in number of cycles. Number of cycles is between 0 and 15.
• TRC: Row Cycle Delay
Reset value is seven cycles.
This field defines the delay between a Refresh and an Activate Command in number of cycles. Number of cycles is
between 0 and 15.
• TRP: Row Precharge Delay
Reset value is three cycles.
This field defines the delay between a Precharge Command and another Command in number of cycles. Number of cycles
is between 0 and 15.
• TRCD: Row to Column Delay
Reset value is two cycles.
This field defines the delay between an Activate Command and a Read/Write Command in number of cycles. Number of
cycles is between 0 and 15.
• TRAS: Active to Precharge Delay
Reset value is five cycles.
This field defines the delay between an Activate Command and a Precharge Command in number of cycles. Number of
cycles is between 0 and 15.
• TXSR: Exit Self Refresh to Active Delay
Reset value is eight cycles.
This field defines the delay between SCKE set high and an Activate Command in number of cycles. Number of cycles is
between 0 and 15.
6384B–ATARM–15-Dec-08
0
0
1
1
CAS
0
1
0
1
CAS Latency (Cycles)
Reserved
1
2
3
AT91SAM9G20 Preliminary
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