Texas Instruments TMS320C64x DSP Benutzerhandbuch

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GPIO Registers
5-23
General Purpose I/O Operation
SPRU629
5.1.11 Video Port Pin Interrupt Status Register (PISTAT)
The video port pin interrupt status register (PISTAT) is shown in Figure 5–11
and described in Table 5–12. PISTAT is a read-only register that indicates the
GPIO pin that has a pending interrupt.
A bit in PISTAT is set when the corresponding GPIO pin is configured as an
interrupt (the corresponding bit in PIEN is set, the pin is enabled for GPIO in
PFUNC, and the pin is configured as an input in PDIR) and the appropriate
transition (as selected by the corresponding PIPOL bit) occurs on the pin.
Whenever a PISTAT bit is set to 1, the GPIO bit in VPIS is set. The PISTAT bits
are cleared by writing a 1 to the corresponding bit in PICLR. Writing a 0 has
no effect. Clearing all the PISTAT bits does not clear the GPIO bit in VPIS, it
must be explicitly cleared. If any bits in PISTAT are still set when the GPIO bit
is cleared, the GPIO bit is set again.
Figure 5–11.Video Port  Pin Interrupt Status Register (PISTAT)
31
24
Reserved
R-0
23
22
21
20
19
18
17
16
Reserved
PISTAT22
PISTAT21
PISTAT20
PISTAT19
PISTAT18
PISTAT17
PISTAT16
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
15
14
13
12
11
10
9
8
PISTAT15
PISTAT14
PISTAT13
PISTAT12
PISTAT11
PISTAT10
PISTAT9
PISTAT8
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
7
6
5
4
3
2
1
0
PISTAT7
PISTAT6
PISTAT5
PISTAT4
PISTAT3
PISTAT2
PISTAT1
PISTAT0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
R-0
Legend: R = Read only; -n = value after reset