Computer Hardware User's 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

Selector

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