ST ST10F276E, User Manual, Page: 174 / 564

Parallel ports UM0404
174/564 DocID13284 Rev 2
XS1PORT (E980h) XBUS Reset Value: 0000h
This register is enabled and visible only when bit XPEN of SYSCON is set, and bit XASCEN
in XPERCON is set as well. On the contrary, the standard P8, DP8 and ODP8 registers
must be used to configure pins P8.6 and P8.7 when XASC is disabled.
6.10.1 Alternate functions of Port8
All Port8 lines (P8.7...P8.0) support capture inputs or compare outputs (CC23IO...CC16IO)
for the CAPCOM2 unit (see
Table 28 ). The use of the port lines by the CAPCOM unit, its
accessibility via software and the precautions are the same as described for the Port2 lines.
As all other capture inputs, the capture input function of pins P8.7...P8.0 can also be used
as external interrupt inputs with a sample rate of eight CPU clock cycles.
Bit Function
XDP8.y
Port direction register bit y (y = 0, 1, 2, 3 only)
‘0’: Port line P8.y is an input (high-impedance).
‘1’: Port line P8.y is an output.
XP8.y Port data register bit y (y = 0, 1, 2, 3 only)
XODP8.y
Port Open Drain control register bit y (y = 0, 1, 2, 3 only)
‘0’: Port line P8.y output driver in push/pull mode.
‘1’: Port line P8.y output driver in open drain mode.
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
-
XOD
P8.7
XP8
.7
XDP8
.7
XOD
P8.6
XP8
.6
XDP8
.6
- RW RW RW RW RW RW
Bit Function
XDP8.y
Port direction register bit y (y = 6, 7 only)
‘0’: Port line P8.y is an input (high-impedance)
‘1’: Port line P8.y is an output
XP8.y Port data register bit y (y = 6, 7 only)
XODP8.y
Port Open Drain control register bit y (y = 6, 7 only)
‘0’: Port line P8.y output driver in push/pull mode
‘1’: Port line P8.y output driver in open drain mode