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IDT Device Controller
Device Control Registers
79RC32438 User Reference Manual
6 - 7
November 4, 2002
Notes
OED
Description:
Output Enable Delay.
This field contains the delay in clock cycles by which the assertion of out-
put enable (OEN) is delayed from the start of a read transaction. Programming this value to be
greater than or equal to RWS causes OEN not be asserted in the transaction.
Initial Value:
0xF
Read Value:
Previous value written
Write Effect:
Modify value
BWD
Description:
Byte Write Enable Delay.
This field contains the delay in clock cycles by which the assertion of
the byte write enable signals (BWEN[1:0]) are delayed from the start of a write transaction. Pro-
gramming this value to be greater than or equal to WWS causes BWEN[1:0] not be asserted in
the transaction.
Initial Value:
0xF
Read Value:
Previous value written
Write Effect:
Modify value
RWS
Description:
Read Wait States.
This field specifies the number of wait states during device read transactions.
A value of zero in this field is treated as an RWS value of one.
Initial Value:
0x3F
Read Value:
Previous value written
Write Effect:
Modify value
WWS
Description:
Write Wait States.
This field specifies the number of wait states during device write transac-
tions. A value of zero in this field is treated as a WWS value of one.
The WWS field must be initialized to a value greater than one if the device is configured to sup-
port burst device write transactions and WAITACKN is configured as a wait input which may be
asserted during the transaction.
Initial Value:
0x3F
Read Value:
Previous value written
Write Effect:
Modify value
BRE
Description:
Burst Read Enable.
When this bit is set, the device controller performs burst device read trans-
actions whenever possible. When this bit is cleared, burst device read transactions are never
generated to the device.
Initial Value:
0x0
Read Value:
Previous value written
Write Effect:
Modify value