MMC2107 Datasheet, PDF (518/618 Pages) –

Freescale Semiconductor, Inc.
External Bus Interface Module (EBI)
NOTE:
The PEPA and PCDPA bits in the ports must also be set to 1 to obtain
full visibility. The waveforms shown in Figure 19-5 describe show
cycles.
19.9.3 Show Strobe (SHS)
The show strobe (SHS) pin provides an indication to an external device
(emulator or logic analyzer) when to latch address, TC[2:0], TSIZ[1:0],
R/W, CSE, PSTAT, and data from the external pins. The SHS pin is
enabled coming out of reset in emulation mode. In master mode, the
SHS pin may be enabled by writing to the port E pin assignment register
(PEPAR).
For any external cycle or show cycle, the SHS pin is driven low to
indicate valid address, TC, TSIZ, R/W, CSE, and PSTAT are present at
the pins, and driven back high to indicate valid data. The SHS pin is
driven low and back high only once per external bus cycle. See
Figure 19-5 and Figure 19-6.
CLKOUT
R/W
A{22:0], TSIZ[1:0]
D[31:0]
INTERNAL CYCLE
EXTERNAL READ
X1
X2
A1
A2
SHOW
DATA
D1
D2
SHS
CSE[1:0]
00
CS
OE
EB[3:0]
TA, TEA
Figure 19-5. Internal (Show) Cycle Followed by External 1-Clock Read
Technical Data
518
External Bus Interface Module (EBI)
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MMC2107 – Rev. 2.0
MOTOROLA