Toshiba TLCS-900/L1 Series Manual page 71

3.5.7 Port B (PB0 to PB6)
Port B0 to PB6 is a 7-bit general-purpose I/O port. Each bit can be set individually for
input or output. Resetting sets port B to be an input port.
In addition to functioning as a general-purpose I/O port, port B0 has clock input
terminal TA0IN of 8-bit timer 0, and port B1, B2 each has facility of 8-bit timer listing
TA1OUT, TA3OUT terminal. And, port B3 to B6 has each external interruption input
facility of INT0 to INT3. Edge selection of external interruption is establishes by IIMC
register in the interrupt controller.
Timer output function and external interrupt function can be enabled by writing 1 to
the corresponding bits in the port B function register (PBFC). Resetting resets all bits of
the registers PBCR and PBFC to 0, and sets all bits to be input ports.
(1) PB0 to PB2
TA0IN
Timer F/F OUT
TA1OUT: TMRA1
TA3OUT: TMRA3
Reset
Direction control
(on bits basis)
PBCR write
S
Output latch
S
B
PB write
Selector
PB read
A
Reset
Direction Control
(on bits basis)
PBCR write
Function control
(on bits basis)
PBFC write
S
Output latch
A S
PB write
Selector
B
B
Selector
PB read
A
S
Figure 3.5.15 Port B0 to B2
91C824-69
TMP91C824
PB0 (TA0IN)
PB1 (TA1OUT)
PB2 (TA3OUT)
2008-02-20