Zilog Z08470 - Manual (Page 241)

Z80 CPU Peripherals
User Manual
UM008101-0601 Serial Input/Output
221
Figure 108. Z80 SIO/4 Pin Assignments
IEI
IEO
M1
+5V
W/RDYA
SYNCA
RxDA
RxCA
TxCA
TxDA
B/A
C/D
RD
GND
W/RDYB
SYNCB
RxDB
RxCB
TxCB
TxDB
DT
RA
RT
S
A
CT
S
A
DCDA
CL
K
RE
S
E
T
DCDB CT
S
B
RT
S
B
DT
RB N/C
Z80
SIO/4
NC
7
8
9
10
11
12
13
14
15
16
17
39
38
37
36
35
34
33
32
31
30
29
INT D7 D5 D3 D1 D0 D2 D4 D6 IO
RQ
CE
N/C
6 5 4 3 2 1 44 43 42 41 40
18 19 20 21 22 23 24 25 26 27 28