Toshiba TLCS-900 Computer Hardware User Manual


 
TMP92CM22
2007-02-16
92CM22-52
3.5.1 Port 1 (P10 to P17)
Port1 is an 8-bit general-purpose I/O port. Bits can be individually set as either
inputs or outputs by control register P1CR and function register P1FC.
In addition to functioning as a general-purpose I/O port, port1 can also function as a
data bus (D8
to D15).
After released reset, device set port1 to pins of follow function by combination of AM1
and AM0 pins.
AM1 AM0 Function Setting after Reset
0 0 Don’t use this setting
0 1 Data bus (D8 to D15)
1 0 Input port (P10 to P17)
1 1 Don’t use this setting
Figure 3.5.1 Port 1
Internal data bus
Direction control
(on bit basis)
Reset
P1CR write
Output latch
P1 write
S
A
Selector
B
P1 Read
External access (Data write)
Port 1
P10 to P17
(D8 to D15)
Function control
(on byte batch)
P1FC write
D8 to D15
External access (Data read)
Output buffer