AT91SAM9G45PRE Datasheet, PDF (855/1218 Pages) ATMEL Corporation – DDR2 Controller 4-bank DDR2/LPDDR, SDRAM/LPSDR

• DETACH: Detach Command
Read:
0 = UDPHS is attached.
1 = UDPHS is detached, UTMI transceiver is suspended.
Write:
0 = pull up the DP line (attach command).
1 = simulate a detach on the UDPHS line and force the UTMI transceiver into suspend state (Suspend M = 0).
(See PULLD_DIS description below.)
• REWAKEUP: Send Remote Wake Up
Read:
0 = Remote Wake Up is disabled.
1 = Remote Wake Up is enabled.
Write:
0 = no effect.
1 = force an external interrupt on the UDPHS controller for Remote Wake UP purposes.
An Upstream Resume is sent only after the UDPHS bus has been in SUSPEND state for at least 5 ms.
This bit is automatically cleared by hardware at the end of the Upstream Resume.
• PULLD_DIS: Pull-Down Disable
When set, there is no pull-down on DP & DM. (DM Pull-Down = DP Pull-Down = 0).
Note: If the DETACH bit is also set, device DP & DM are left in high impedance state.
(See DETACH description above.)
DETACH
0
0
1
1
PULLD_DIS
0
1
0
1
DP
Pull up
Pull up
Pull down
High impedance
state
DM
Pull down
High impedance
state
Pull down
High impedance
state
Condition
not recommended
VBUS present
No VBUS
VBUS present &
software disconnect
855 AT91SAM9G45
6438F–ATARM–21-Jun-10