Z8 cpu (see, Figure 23 – Zilog Z86193 User Manual
Page 43
Z8
®
CPU
User Manual
UM001604-0108
Reset
36
Figure 23. Example of External Power-On Reset Circuit
Table 13. ERF Bank 0 Reset Values at RESET
Register
(Hex)
Register Name
Bits
Comments
7
6
5
4
3
2
1
0
00
Port 0
U U U U U U U U Input mode, output set to push–pull.
01
Port 1
U U U U U U U U Input mode, output set to push–pull.
02
Port 2
U U U U U U U U Input mode, output set to open
drain.
03
Port 3
1
1
1
1
U U U U Standard digital input and output
Z86L7X Family Device Port P34-
P37 = 0
(Except Z86L70/71/75)
All other Z8 = 1.
04–EF
General-Purpose
Registers 04h–EFh
U U U U U U U U Undefined.
Table 14. Sample Expanded Register File Bank C Reset Values
Register
(Hex)
Register Name
Bits
Comments
7
6
5
4
3
2
1
0
00
SPI Compare (SCOMP)
0
0
0
0
0
0
0
0
01
Receive Buffer (RxBUF)
U
U
U
U
U
U
U
U
02
SPI Control (SCON)
U
U
U
U
0
0
0
0
1
µF
+5V
100 K
Ω
RESET
1 K
to
200 K
Ω
10 V