External Bus Interface
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
9-43
Figure 9-30. Reservation on Local Bus
The MPC561/MPC563 samples the CR line at the rising edge of CLKOUT. When this signal is asserted,
the reservation flag is reset (negated).
The external bus interface (EBI) samples the logical value of the reservation flag prior to externally
starting a bus cycle initiated by the RCPU stwcx instruction. If the reservation flag is set, the EBI begins
with the bus cycle. If the reservation flag is reset, no bus cycle is initiated externally, and this situation is
reported to the RCPU.
The reservation protocol for a multi-level (local) bus is illustrated in
. The system describes the
situation in which the reserved location is sited in the remote bus.
S
R
Reservation
Logic
External Bus
Interface
lwarx
Q
En
a
b
le
e
x
te
rn
a
l
st
w
cx
a
cce
ss
CR
External Bus
Bus
ADDR[0:29]
CR
CLKOUT
AT[0:3], RSV, R/W,
TS
MPC500 Device
Master
Summary of Contents for MPC561
Page 84: ...MPC561 MPC563 Reference Manual Rev 1 2 lxxxiv Freescale Semiconductor...
Page 144: ...Signal Descriptions MPC561 MPC563 Reference Manual Rev 1 2 2 46 Freescale Semiconductor...
Page 206: ...Central Processing Unit MPC561 MPC563 Reference Manual Rev 1 2 3 62 Freescale Semiconductor...
Page 302: ...Reset MPC561 MPC563 Reference Manual Rev 1 2 7 14 Freescale Semiconductor...
Page 854: ...Time Processor Unit 3 MPC561 MPC563 Reference Manual Rev 1 2 19 24 Freescale Semiconductor...
Page 968: ...Development Support MPC561 MPC563 Reference Manual Rev 1 2 23 54 Freescale Semiconductor...
Page 1144: ...Internal Memory Map MPC561 MPC563 Reference Manual Rev 1 2 B 34 Freescale Semiconductor...
Page 1212: ...TPU3 ROM Functions MPC561 MPC563 Reference Manual Rev 1 2 D 60 Freescale Semiconductor...
Page 1216: ...Memory Access Timing MPC561 MPC563 Reference Manual Rev 1 2 E 4 Freescale Semiconductor...