C8051F93X Datasheet, PDF (227/330 Pages) Silicon Laboratories – Pipelined intstruction architecture executes 70 of instruction in 1 or 2 system clocks

C8051F93x-C8051F92x
21.4. Port Match
Port match functionality allows system events to be triggered by a logic value change on P0 or P1. A
software controlled value stored in the PnMAT registers specifies the expected or normal logic values of P0
and P1. A Port mismatch event occurs if the logic levels of the Port’s input pins no longer match the
software controlled value. This allows Software to be notified if a certain change or pattern occurs on P0 or
P1 input pins regardless of the XBRn settings. Note: On C8051F931/21 devices, Port Match is not
available on P1.6 or P1.7.
The PnMASK registers can be used to individually select which P0 and P1 pins should be compared
against the PnMAT registers. A Port mismatch event is generated if (P0 & P0MASK) does not equal
(PnMAT & P0MASK) or if (P1 & P1MASK) does not equal (PnMAT & P1MASK).
A Port mismatch event may be used to generate an interrupt or wake the device from a low power mode.
See Section “12. Interrupt Handler” on page 136 and Section “14. Power Management” on page 159 for
more details on interrupt and wake-up sources.
SFR Definition 21.4. P0MASK: Port0 Mask Register
Bit
7
6
5
4
3
2
1
0
Name
P0MASK[7:0]
Type
R/W
Reset
0
0
0
0
0
0
0
0
SFR Page= 0x0; SFR Address = 0xC7
Bit
Name
Function
7:0 P0MASK[7:0] Port0 Mask Value.
Selects the P0 pins to be compared with the corresponding bits in P0MAT.
0: P0.n pin pad logic value is ignored and cannot cause a Port Mismatch event.
1: P0.n pin pad logic value is compared to P0MAT.n.
SFR Definition 21.5. P0MAT: Port0 Match Register
Bit
7
6
5
4
3
2
1
0
Name
P0MAT[7:0]
Type
R/W
Reset
1
1
1
1
1
1
1
1
SFR Page= 0x0; SFR Address = 0xD7
Bit
Name
Function
7:0 P0MAT[7:0] Port 0 Match Value.
Match comparison value used on Port 0 for bits in P0MASK which are set to 1.
0: P0.n pin logic value is compared with logic LOW.
1: P0.n pin logic value is compared with logic HIGH.
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