Toshiba H1 Series Data Book page 124

3.7.3 Port 5 (P50 to P57)
Port5 is an 8-bit general-purpose Output ports. In addition to functioning as a
general-purpose I/O port, port5 can also function as an address bus (A8 to A15). Each bit
can be set individually for function. Setting the AM1 and AM0 pins as shown below and
resetting the device initialize port 5 to the following function pins:
AM1
0
0
1
1
A8 to A15
Read data
AM0 Function Setting after reset is released
0 Don't use this setting
1 Address bus (A8 ~ A15)
0 Don't use this setting
1 Output port (P50 ~ P57)
P5FC Register
P5 Register
Figure 3.7.5 Port5
92CZ26A-121
S
0
1
Selector
TMP92CZ26A
P50 to P57
(A8 to A15)