Apple Lisa - Baud Rate Generation

Confidential
Lisa Hardware Reference Manual
BAUD RATE GENERATION
The baud rate generator produces standard baud rates as well as a
baud
rate that is under the control of the 6522. The 6522 controlled
rate can range from less than one baud up to about 1000 baud. Since
the Tl timer in the Hard Disk Interface's 6522 is connected to the
baud rate generator via PB7, either data communications channel can
use the 6522 timer for baud rate control. The baua rate generator
has seven control line inputs (CO-C6) which are _set or reset by
control pulses.
BAliD RATE CONTROL LINES
Channel 1
CCC
210
000
001
010
011
100
101
110
111
Channel
CCC
654
2
Baud
Rate
External Clock
6522
control
300 baud
1200 baud
2400 baud
4800 baud
9600 baud
19200 baud
Baud Rate
000 6522 control
001 300 baud
010 600 baud
011 1200 baud
100 2400 baud
101 4800 baud
110 9600 baud
111 19200 baud
C3 Receiver Clock
o same as transmitter clock
1 external clock (for synchronous communications)
Page 40
7-Jul-81