Encore electronic Zilog Z8ENCORE000ZCO - Manual (Page 19)

Z8 Encore!
®
Flash Microcontroller Development Kit
User Manual
15
UM014605-0208 Z8 Encore!® Evaluation Board
Serial Communications Devices
I
2
C Interface
The Z8 Encore! is compatible with I
2
C protocol (in this case the
PCA8550). The I
2
C controller consists of two bidirectional bus lines, a
serial data (SDA) line and a serial clock (SCL) line.
The I
2
C Controller operates in Master mode to transmit and receive data.
Having a PCA8550 on board enables configuration of the Expansion
Module. The PCA8550 is a 4-bit multiplexer that selects four bits of data
either from a non-volatile register or from the input pins. In this case four
input pins are left unconnected and only a non-volatile register is selected
as a source of data. Only three bits are used. Currently this chip is not
used by the software provided with the board, so you can use it to your
Table 2. LED Cathode/Modem/Trigger
Function/Port E Bit No 4 3 2 1 0
Cathode Column 0 X
Cathode Column 1 X
Cathode Column 2 X
Cathode Column 3 X
Cathode Column 4 X
Note: Column 0 = Leftmost Column
Table 3. LED Addressing
Function/Port, Bit No PE[5] PE[6] PE[7] PG[7]
D3 X
D4
X
D1 X
D2 X