9.9 Port 8
9.9.1 Overview
Port 8 is an 8-bit input port that also receives inputs for the on-chip A/D converter. The pin
functions are the same in all MCU operating modes, as shown in figure 9-20.
9.9.2 Port 8 Registers
Register Configuration: Port 8 has only the data register described in table 9-14. Since it is
exclusively an input port, there is no data direction register.
Table 9-14 Port 8 Registers
Name Abbreviation Read/Write Address
Port 8 data register P8DR R H'FF8F
1. Port 8 Data Register (P8DR)—H'FF8F
When the CPU reads P8DR it always reads the current status of each pin, except that during A/D
conversion the pin currently being converted reads “1” regardless of the actual input voltage at that
pin.
P87 (input) / AN7 (input)
P8
6 (input) / AN6 (input)
P8
5 (input) / AN5 (input)
Port P8
4 (input) / AN4 (input)
8P8
3 (input) / AN3 (input)
P8
2 (input) / AN2 (input)
P8
1 (input) / AN1 (input)
P8
0 (input) / AN0 (input)
Bit 76543210
P8
7 P86 P85 P84 P83 P82 P81 P80
Initial value 00000000
Read/Write RRRRRRRR
Figure 9-20 Pin Functions of Port 8
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