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Zilog EZ80L92 User Manual

Page 28

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eZ80L92 Development Kit
User Manual

Operational Description

UM012913-0407

24

General-Purpose Port
The general-purpose port is emulated using GPIO Output Control
Register and the GPIO Data Register. If bit 7 in the GPIO Output Control
Register is 1, all the lines on the general-purpose port are configured as
inputs. If this bit is 0, all the lines on the general-purpose port are
configured as outputs.

Table 7

lists the multiple functions of the register.

The GPIO Data Register receives inputs or provides outputs for each of
the seven general-purpose port lines, depending on the configuration of
the port. See

Table 8

.

Table 6. LED and Port Emulation Addresses

Address

Register Function

Access

800000h

LED Anode/General-Purpose Port
Output Control

WR

800001h

LED Cathode/Modem/Trig

WR

800002h

General-Purpose Port Data

RD/WR

Table 7. LED Anode/General-Purpose Port Output Control Register

Function

Bit No.

7

6

5

4

3

2

1

0

Anode Col 1

X

Anode Col 2

X

Anode Col 3

X

Anode Col 4

X

Anode Col 5

X

Anode Col 6

X

GPIO Output

X