MPC5553/MPC5554 Microcontroller Reference Manual, Rev. 5
Freescale Semiconductor 12-41
12.4.2.6.1 Small Access Example #1: 32-bit Write to 16-bit Port
Figure 12-27 shows an example of a 32-bit write to a 16-bit port, requiring two 16-bit external transactions.
Figure 12-27. Single Beat 32-bit Write Cycle, 16-bit Port Size, Basic Timing
12.4.2.6.2 Small Access Example #2: 32-byte Write with External TA
Figure 12-28 shows an example of a 32-byte write to a non-chip select device, such as an external master,
using external TA, requiring eight 32-bit external transactions. Note that due to the use of external TA,
RD_WR does not toggle between the accesses unless that access is the end of a 64-bit boundary. In this
case, an extra cycle is required between TA and the next TS in order to get the next 64-bits of write data
internally and RD_WR negates during this extra cycle.
DATA is validDATA is valid
CLKOUT
ADDR[8:31]
TS
DATA[0:31]
TA
RD_WR
TSIZ[0:1]
BDIP
WE
CSx
10
AA+2
ABCDXXXX EFGHXXXX
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