MPC563XM Reference Manual, Rev. 1
386
Freescale Semiconductor
Preliminary—Subject to Change Without Notice
13.5.2.11 Non-Chip-Select Burst in 16-bit Data Bus Mode
The timing diagrams in this section apply only to the special case of a non-chip-select 32-bit access in
16-bit data bus mode (DBM=1 in EBI_MCR). These diagrams specify the behavior for both the
EBI-master and EBI-slave, as the external master is expected to be another MCU with this EBI.
For this case, a special 2-beat burst protocol is used for reads and writes, so that the EBI-slave can
internally generate one 32-bit read or write access (thus 32-bit coherent), as opposed to two separate 16-bit
accesses. This behavior is independent of the width of the internal AMBA bus. So even with a 32-bit
AMBA bus, 32-bit accesses are coherent (just as for default 64-bit AMBA bus).
shows a 32-bit read from an external master in 16-bit data bus mode.
shows a 32-bit write from an external master in 16-bit data bus mode.