Table 8 – Zilog EZ80L92 User Manual

Page 29

eZ80L92 Development Kit

User Manual

UM012913-0407

Operational

Description

Reading from the general-purpose port can damage the drivers used for
the general-purpose port and memory. The port can, however, be used for
writing data.

LED Matrix
The one 7 x 5 LED matrix device on the eZ80Acclaim!

Development

Platform is a memory-mapped device that can be used to display informa-
tion, such as programmed alphanumeric characters. For example, the
LED display sample program that is shipped with this kit displays the
alphanumeric message:

eZ80

To illuminate any LED in the matrix, its respective anode bit must be set
to 1 and its corresponding cathode bit must be set to 0.

Bits 0–6 in

Table 7

are LED anode bits. They must be set High (1) and

their corresponding cathode bits, bits 0–4 in

Table 9

, must be set Low (0)

to illuminate each of the LED’s, respectively.

Bit 7 in

Table 7

does not carry any significance within the LED matrix. It