Toshiba – Toshiba TMP87CP24AF User Manual
Page 60
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TOSHIBA
TMP87CM24A/P24A
2.2.7 Ports P6 (P67 to P60) Port P7 (P77 to P70) Port P8 (P87 to P80) Port P9 (P93 to P90)
Port P
6
, P7, P
8
and P9 are an
8
-bit input/output ports and are also used as the segment output port.
Input/output mode or segement output mode is specified by the corresponding bit in the Px port control
register (PxCR). During reset, PxCR is initialized to "0", which configure port Px as input/output. Port Px
output latches are also initialized to "1". PxCR can only be written.
When a read instruction is executed for port P9, bits 7 to 4 read in as indefinite.
Note: x = 6,7,8,9
Example: Setting the upper 2 bits of port P
6
as a segment output port, and the others as
input/output port.
LD
(P
6
CR), 11000000B
P6
(0006
h
)
R/W
P6CR
(0029
h
)
P7
(0007
h
)
R/W
P7CR
(002A
h
)
P8
(0008
h
)
R/W
P8CR
(002B
h
)
P9
(0009
h
)
R/W
P9CR
(002C
h
)
P67
SEG16
P66
SEG17
P65
SEG18
P64
SEG19
P63
SEG20
P62
SEG21
P61
SEG22
P60
SEG23
1
0
(Initial value:
1111 1111)
(Initial value:
0000 0000)
P6CR
Port P6/
segment output select
0: Port P6 mode
1: Segment output mode
1
0
P77
SEG24
P76
SEG25
P75
SEG26
P74
SEG27
P73
SEG28
P72
SEG29
P71
SEG30
P70
SEG31
1
0
(Initial value:
1111 1111)
(Initial value:
0000 0000)
P7CR
Port P7/
segment output select
0: Port P7 mode
1: Segment output mode
1
0
P87
SEG32
P86
SEG33
P85
SEG34
P84
SEG35
P83
SEG36
P82
SEG37
P81
SEG38
P80
SEG39
1
0
(Initial value:
1111 1111)
(Initial value:
0000 0000)
P8CR
Port P8/
segment output select
0: Port P8 mode
1: Segment output mode
1
0
P93
SEG12
P92
SEG13
P91
SEG14
P90
SEG15
1
0
(Initial value:
1111 1111)
(Initial value:
0000 0000)
Figure 2-9. Port P
6
, P7, P
8
, P9
Write-
only
Write-
only
Write-
only
P9CR
Port P9/
0: Port P9 mode
Write-
segment output select
1: Segment output mode
only
3
-
24-60
2002
-
10-03