TMP91C824
91C824-62
2008-02-20
3.5.4
Port 6 (P60 to P67)
Port 60 to 67 are 8-bit output ports. Resetting sets output latch of P62 to 0 and output
latches of P60 to P61, P63 to P67 to 1.
Port 6 also function as chip-select output (
CS0
to
CS3
), extend address output (EA24).
Writing 1 in the corresponding bit of P6FC, P6FC2 enables the respective functions.
Resetting resets the P6FC, P6FC2 to 0, and sets all bits to output ports.
If set port 6, be careful of a setting because of chip select function.
Starting memory connects to CS2 pin, but this signal function as P62 after reset.
Therefore initialized value of output data of P62 is set to “0”. If manage chip select by
connection many memory to outside, after program started, must to change port function
to chip select function in this program. If outputted “1” remain port function, program is
not run. Therefore data setting (P6) must to execute after function changing (P6FC).
Figure 3.5.7 Port 6
Funtion
control
(on bit basis)
Output
lacth
P6 read
Reset
P60 (
CS0
),
P61 (
CS1
),
P62 (
CS2
,
CS2A
)
P63 (
CS3
),
P64 (EA24,
CS2B
)
P65 (EA25,
CS2C
)
P66 (
CS2D
)
P67 (
CS2E
)
CS0
,
CS1
,
CS2
,
CS3
, EA24, EA25
Selector
P6FC write
P6 write
S
A
B
P6FC2 write
1, 1,
CS2A
, 1,
CS2B
C
Int
er
nal dat
a
b
us
Function
control 2
(on bit basis)