z80180 ZiLOG Semiconductor, z80180 Datasheet - Page 80

• Manufacturer Part Number: z80180
• Description: Microprocessor Unit
• Manufacturer: ZiLOG Semiconductor

I/O Control Register (ICR)
I/O Control Register (ICR: I/O Address = 3Fh)
PS014004-1106
Bit
Note:
ICR
the
IOA7, 6: I/O Address Relocation (bits 7,6)
IOA7
IOSTP:
I/O operation resumes when
IOSTOP
IOA7
R/W
allows relocating of the internal I/O addresses.
7
and
IOA7– IOA6 = 0 1
IOA7–IOA6 = 0 0
IOA7–IOA6 = 1 0
Figure 78. I/O Control Register (ICR: I/O Address = 3Fh)
The high-order 8 bits of 16-bit internal I/O address are always 0.
cleared to
IOA7–IOA6 = 1 1
IOSTOP
IOA6
IOA6
mode
R/W
6
relocate internal I/O as illustrated in
Mode (bit 5)—
(Figure
0
Figure 79. I/O Address Relocation
IOSTP
during
R/W
5
78).
RESET
IOSTOP
4
—
.
IOSTOP
is reprogrammed or
3
—
mode is enabled when
2
—
00FFh
00C0h
00BFh
0080h
0070h
0040h
003Fh
0000h
ICR
Figure
1
—
also controls enabling/disabling of
RESET
79.
0
—
to
IOSTP
Microprocessor Unit
0
.
is set to
IOA7
and
Architecture
1
. Normal
Z80180
IOA6
are
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