Motorola MPC823e Reference Manual page 303

MPRE—Multiprocessors Reservation Enable
If this bit is set, then the interprocessor reservation protocol is enabled. The RSV pin
functions as defined in Section 13.4.10 Storage Reservation Protocol.
0 = RSV/IRQ2 functions as IRQ2.
1= RSV/IRQ2 functions as RSV.
MLRC—Multi-Level Reservation Control
This field configures the functionality of the KR/RETRY/IRQ4/SPKROUT pins.
00 = KR/RETRY/IRQ4/SPKROUT functions as IRQ4.
01 = KR/RETRY/IRQ4/SPKROUT is three-stated.
10 = KR/RETRY/IRQ4/SPKROUT functions as KR/RETRY.
11 = KR/RETRY/IRQ4/SPKROUT functions as SPKROUT.
AEME—Asynchronous External Master Enable
This bit configures how the memory controller refers to external asynchronous masters
initiating a transaction. If this bit is set, the memory controller interprets any assertion on the
AS pin as an external asynchronous master initiating a transaction. If it is reset, the memory
controller ignores the value of the AS pin. This bit and the GPLA4DIS bit of the machine A
mode register (described in Section 15.3.1.5 Machine A Mode Register) controls the
direction and functionality of the UPWAITA/GPL_A4/AS pins.
AEME GPLA4DIS
X 0
0 1
1 1
SEME—Synchronous External Master Enable
This bit configures how the memory controller refers to external synchronous masters
initiating a transaction. If this bit is set, the memory controller interprets any assertion on the
TS pin the external bus does not own as an external synchronous master initiating a
transaction. If it is reset, the memory controller ignores the value of the TS pin when it does
not own the external bus. When the MPC823e owns the bus, the memory interprets the
assertion of the TS pin as an internal request.
GB5E—GPL_B5 Enable
0 = The BDIP functionality is active.
1 = The GPL_B5 of the memory controller functionality is active.
B2DD—Bank 2 Double Drive
If this bit is set, the CS2 signal is reflected on GPL_x2.
MOTOROLA
PIN USAGE
Functions as GPL_A4
Functions as UPWAIT
Functions as AS
MPC823e REFERENCE MANUAL
System Interface Unit
UPWAIT AS VALUE
VALUE
GND VCC
Pin value VCC
GND Pin value
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