Zilog EZ80190 - Manual (Page 30)

eZ80190 Development Kit
User Manual
eZ80Acclaim! Development Platform UM014108-0810
26
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
is used for the general-purpose port as a control bit.
Table 9 indicates the multiple register functions of the LED cathode,
modem, and triggers. This table shows the bit configuration for each cath-
ode bit. Bits 5, 6, and 7 do not carry any significance within the LED
matrix. These three bits are control bits for the modem reset, Trig1, and
Trig2 functions, respectively.
Table 9. Bit Access to the LED Cathode, Modem, and Triggers
Function
Bit #
7 6 5 4 3 2 1 0
Cathode Row 5 X
Cathode Row 4 X
Cathode Row 3 X
Cathode Row 2 X