Rainbow Electronics AT91CAP9S250A - Manual (Page 241)

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6264A–CAP–21-May-07
AT91CAP9S500A/AT91CAP9S250A
This field is unique to Mobile SDRAM. It is used to program the refresh interval during self refresh mode, depending on
the case temperature of the low-power SDRAM.
The values of this field are dependent on Mobile SDRAM devices.
After the initialization sequence, as soon as TCR field is modified and self refresh mode is activated, Extended Mode Reg-
ister is accessed automatically and TCR bits are updated before entering in self refresh mode.
• DS: Drive strength
Reset value is “0”.
This field is unique to Mobile SDRAM. It selects the driver strength of SDRAM output.
After the initialization sequence, as soon as DS field is modified and self refresh mode is activated, Extended Mode Regis-
ter is accessed automatically and DS bits are updated before entering self refresh mode.
• TIMEOUT
Reset value is “00”.
This field defines when low-power mode is enabled.
00 The SDRAM controller activates the SDRAM low-power mode immediately after the end of the last transfer.
01 The SDRAM controller activates the SDRAM low-power mode 64 clock cycles after the end of the last transfer.
10 The SDRAM controller activates the SDRAM low-power mode 128 clock cycles after the end of the last transfer.
11 Reserved