st20-gp1 STMicroelectronics, st20-gp1 Datasheet - Page 85

• Manufacturer Part Number: st20-gp1
• Description: Gps Processor
• Manufacturer: STMicroelectronics

14 Parallel input/output
The ST20-GP1 device has 6 bits of Parallel Input/Output (PIO), each bit is programmable as an
input or an output.
The input bits can be compared against a register and an interrupt generated when the value is not
equal.
14.1 PIO Port
Each of the bits of the PIO port has a corresponding bit in the PIO registers associated with the
port. These registers hold: output data for the port (POut); the input data read from the pin (PIn);
PIO bit configuration register (PC1); and the two input compare function registers (PComp and
PMask).
All of the registers, except the PIn register, are each mapped onto three separate addresses so
that bits can be set or cleared individually.
The Set_ register allows bits to be set individually. Writing a ‘1’ in this register sets the
corresponding bit in the associated register, a ‘0’ leaves the bit unchanged.
The Clear_ register allows bits to be cleared individually. Writing a ‘1’ in this register resets the
corresponding bit in the associated register, a ‘0’ leaves the bit unchanged.
14.1.1 PIO Data registers
The base addresses for the PIO registers are given in the Memory Map chapter.
POut register
This register holds output data for the port.
POut
Bit
0
1
2
3
4
5
Bit field
POut0
POut1
POut2
POut3
POut4
POut5
PIO port base address + #00
Function
Output data bit 0
Output data bit 1
Output data bit 2
Output data bit 3
Output data bit 4
Output data bit 5
Table 14.1 POut register format
Read/Write
ST20-GP1
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