ZiLOG System 8000

HRM
Zilog HRM
Table 4-8
Parallel Printer Data, Port
B
BIT NUMBER
CENTRONICS DATA
PRODUCTS
Bi.t
0
Data Bit
0
Data Bit
0
Bi.t
1
Data Bit
1
Data Bit
1
Bi.t
2
Data
Bit
2
Data Bit
2
Bi.t
3
Data
Bit
3
Data Bit
3
Bi.t
4
Data
Bit 4 Data Bit
4
Bit
5
Data Bit
5
Data
Bit
5
Bi.t
6
Data Bit
6
Data Bit
6
4.5.1.2 Serial I/O: The serial 1/0 comprises 4 Z80B-SIO/2
devices. Each device has two channels; Table 4-9 lists the
devices and their assigned channels.
Table 4-9
DEVICE NUMBER
SIO 0
SIO 1
SIO 2
SIO
3
Serial I/O Devices and Channel Assignments
CHANNEL ASSIGNMENT
Channels 0 and 1
Channels 2 and 3
Channels 4 and 5
Channels 6 and 7
Each channel of the serial IIO connects to its own baud-rate
generator. These generators are channels in Z80B-CTC dev-
ices. The SIO channels and their corresponding baud-rate
generators are listed in Table 4-10~ The baud rate clock
comes from an independent baud-rate oscillator. The fre-
quency of the baud-rate clock is 1.2288 megahertz.
4-13
Zilog
4-13