Octagon 5266, Справочное руководство

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Table 8–5 I/O port byte
Bit
7 Bit
6 Bit
5 Bit
4 Bit
3 Bit
2 Bit
1 Bit
0 Port I/O
Line
X 7
X 6
X 5
X 4
X 3
X 2
X 1
X 0
For example, writing 00011100 to port C (base a 2) will configure port C
I/O lines 0, 1, 5, 6, and 7 to be inputs and lines 2, 3, and 4 to be outputs:
OUT 1052h, 1Ch (00011100 binary = 1C hexadecimal)
3. Write a “1” to the control register (base re 3). This places the I/O chip
into “preset” mode:
OUT 1053h, 1 (control register, preset mode)
4. Write a bit pattern to appear at the outputs of the desired I/O port when the
I/O chip is put in “operation” mode; all input bits are unaffected.
5. Write a “3” to the control register (base re 3). This places the I/O chip
back into “operation” mode:
OUT 1053h, 3 (control register)
Writing and reading from I/O
Writing to or reading from the desired I/O port is accomplished with single
program statements:
1. To write a bit pattern to the desired I/O port:
OUT 1052h, FFh
All output bits of port C go high; all input bits are unaffected.
2. To read a bit pattern from the desired I/O port:
PORTC = INP(1052h)
The byte read from port C is assigned to variable PORTC.
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