Rainbow Electronics AT91CAP9S250A - Manual (Page 227)

227
6264A–CAP–21-May-07
AT91CAP9S500A/AT91CAP9S250A
23.4.4.3 Deep Power-down Mode
The deep power-down mode is a new feature of the Mobile SDRAM. When this mode is acti-
vated, all internal voltage generators inside the device are stopped and all data is lost.
This mode is activated by setting the low-power command bits [LPCB] to ‘11’. When this mode is
enabled, the DDRSDRC leaves normal mode (mode == 000) and the controller is frozen. To exit
deep power-down mode, an initialization sequence must be generated by software: (see
Section
23.3.3 ”Mobile DDR-SDRAM Initialization” on page 215 ).
Figure 23-16. Deep Power-down Mode Entry
NOP READ BST NOP PRCHG NOP DEEPOWER NOP
0
Trp
Enter Deep
Power-down
Mode
SDCLK
A[12:0]
COMMAND
CKE
BA[1:0]
DQS[1:0]
Da Db
D[15:0]
3
DM[1:0]