Memory Controller
MPC561/MPC563 Reference Manual, Rev. 1.2
Freescale Semiconductor
10-29
Because it takes two clocks for the external address to be recognized and handled by the memory
controller, the TS which is generated by the external master is ahead of the corresponding CS and strobes
which are asserted by the memory controller. This 2-clock delay might cause problems in some
synchronous memories. To overcome this, the memory controller generates the MTS (memory transfer
start) strobe which can be used in the slave’s memory instead of the external master’s TS signal. As seen
in
, the MTS strobe is synchronized to the assertion of CS by the memory controller so that
the external memory can latch the external master’s address correctly. To activate this feature, the MTSC
bit must be set in the SIUMCR register. Use external logic to control devices that can have burst accesses
from an external master.
On the MPC563, when the external master accesses the internal Flash when it is disabled, the access is
terminated with the transfer error acknowledge (TEA) signal asserted, and the memory controller does not
support this access in any way.
When the memory controller serves an external master, the BDIP signal becomes an input signal. This
signal is watched by the memory controller to detect when the burst is terminated.
Figure 10-20. Synchronous External Master
Configuration for GPCM-Handled Memory Devices
Memory
Address
CE
OE
W
Data
Address
CSx
OE
WE/BE
Data
Synchronous External Master
TS
TA
TA
TS
ADDR
Data
BDIP
BDIP
BDIP
BURST
NOTE: The memory controller’s BDIP line is used as a burst_in_progress signal.
BURST
BURST
MTS
TS
MPC5xx
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...