SM8521 Datasheet, PDF (29/56 Pages) Sharp Electrionic Components – 8-Bit Single-Chip Microcomputer

I/O PORTS
The SM8521 supports four 8-bit I/O ports. Each
port can be selected one out of input, outpit, input
with built-in pull-up resistor and open-drain in each
2-bit.
Internal Bus
Data register
Control register
SM8521
I/O control circuit
Input/output
pins
Fig. 12 PIO Block Diagram
P0 to P3 (PIO data register)
Bit 7
0
PX7 PX6 PX5 PX4 PX3 PX2 PX1 PX0
(x = 0, 1, 2, 3)
NOTE :
In case of reading P0-P3 register on condition that control
register is input state, data of those pins is read. In case of
on condition that control register is output state, data of
register is read.
P0C to P2C (PIO control register)
Bit 7
0
PXC7 PXC6 PXC5 PXC4 PXC3 PXC2 PXC1 PXC0
(x = 0, 1, 2)
Bits 3 to 2 :
BIT
CONTENT
00 Input
01 Input (with pull-up resistor)
10 Output
11 Output (open-drain)
Bits 1 to 0 :
BIT
CONTENT
00 Input
01 Input (with pull-up resistor)
10 Output
11 Output (open-drain)
Bits 7 to 6 :
BIT
CONTENT
00 Input
01 Input (with pull-up resistor)
10 Output
11 Output (open-drain)
Bits 5 to 4 :
BIT
CONTENT
00 Input
01 Input (with pull-up resistor)
10 Output
11 Output (open-drain)
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