SAM3X8E Atmel Corporation, SAM3X8E Datasheet - Page 410

• Manufacturer Part Number: SAM3X8E
• Manufacturer: Atmel Corporation

Figure 25-4. Read Burst with Boundary Row Access
25.6.4
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410
SDRAMC_A[12:0]
SDWE
SDCS
SDCK
DATA
RAS
CAS
SAM3X/A
SAM3X/A
SDRAM Controller Refresh Cycles
col a
Row n
col b
Dna
An auto-refresh command is used to refresh the SDRAM device. Refresh addresses are gener-
ated internally by the SDRAM device and incremented after each auto-refresh automatically.
The SDRAM Controller generates these auto-refresh commands periodically. An internal timer is
loaded with the value in the register SDRAMC_TR that indicates the number of clock cycles
between refresh cycles.
A refresh error interrupt is generated when the previous auto-refresh command did not perform.
It is acknowledged by reading the Interrupt Status Register (SDRAMC_ISR).
col c
Dnb
col d
Dnc
Dnd
T
RP
= 3
Row m
T
RCD
= 3
col a
CAS = 2
col b
Dma
col c
Dmb
col d
Dmc
11057A–ATARM–17-Feb-12
11057A–ATARM–17-Feb-12
col e
Dmd
Dme