Signal Descriptions
5-12
MPC821FADS-DB USER’S MANUAL
MOTOROLA
Table 5-9. PM1 Interconnect Signals
PIN
MOTHERBOARD
SIGNAL
DAUGHTERBOARD
SIGNAL
INPUT/
OUTPUT
DESCRIPTION
1
BB
BB
I/O, L
Bus Busy signal. Pulled up on this board.
2
VCC
VCC
—
3
DRM_W
DRM_W
I,L
DRAM Write signal. GPL0 line used as R/W
signal for the DRAM SIMM or as A10 line for
the SDRAM.
4
VCC
VCC
—
5V Bus
5
TEA
TEA
I/O, L, OD
Transfer Error Acknowledge signal. Pulled up,
but not driven on the board.
6
VCC
VCC
—
7
BR
BR
I/O,L
Bus Request signal. Pulled up on this board,
but otherwise unused.
8
VCC
VCC
—
9
BURST
BURST
I/O, L
Burst signal. Pulled up, but otherwise unused
on this board.
10
VCC
VCC
—
11
GPL4A
GPL4A
X,L
General-Purpose Line 4 of UPMA. Not used on
this board.
12
VCC
VCC
—
13
TA
TA
I/O, L
Transfer Acknowledge signal. Indicates the
end of a bus cycle,. Used with MPC8xxFADS
logic.
14
VCC
VCC
—
15
TS
TS
I/O, L
Transfer Start signal. Pulled up, but otherwise
unused on this board.
16
VCC
VCC
—
17
GPL5B
GPL5B
O, L
General-Purpose Line 5 of UPMB. Not used on
this board.
18
VCC
VCC
—
19
BG
BG
I/O, L
Bus Grant signal. Pulled up, but otherwise
unused on this board.
20
VCC
VCC
—
21
GPL4B
GPL4B
O, L
General-Purpose Line 4 of UPMB. Not used on
this board.
22
VCC
VCC
—
23
R_W
R_W
I/O, L
Read/Write signal. Pulled up on this board and
used by MPC8xxFADS logic.
24
VCC
VCC
—
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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