ZiLOG Z-80 SIB User Manual page 10

1.2 Block Diagram
EIA/RS-232
INTER-
FACE
ElA/RS-232
INTER-
FACE
EIA/RS-232
INTER-
FACE
USART
7^
o
EC
X
tr
"7
USART
CTC
EXTL
CLK
CLK
SEL
RxRDY
TxRDY
CTC
USART
7^
RxRDY
TxRDY
CONTROL
AND EXT
CLK
BUFFER
7^
Ui
o
o
_l
CO
o
_!
X
O
tr
cr
h-
X
O
<
CJ
ill
EIA/RS-232
INTER-
FACE
20
MA
TTY
CURRENT
LOOP
?7
USART
CTC
1/0
ADDRESS
DECODER
7^
DATA
BUS
BUFFER
7^
DATA
BUS
BUFFER
CONTROL
\7
SERIAL INTERFACE BLOCK DIAGRAM