Datasheet

519
SAM4S [DATASHEET]
11100E–ATARM–24-Jul-13
Figure 30-12.Parallel Capture Mode Waveforms (DSIZE=2, ALWYS=0, HALFS=1, FRSTS=0)
Figure 30-13.Parallel Capture Mode Waveforms (DSIZE=2, ALWYS=0, HALFS=1, FRSTS=1)
30.5.13.3Restrictions
 Configuration fields DSIZE, ALWYS, HALFS and FRSTS in PIO_PCMR (“PIO Parallel Capture Mode Register” )
can be changed ONLY if the parallel capture mode is disabled at this time (PCEN = 0 in PIO_PCMR).
 Frequency of PIO controller clock must be strictly superior to 2 times the frequency of the clock of the device which
generates the parallel data.
30.5.13.4Programming Sequence
Without PDC
1. Write PIO_PCIDR and PIO_PCIER (“PIO Parallel Capture Interrupt Disable Register” and “PIO Parallel Capture
Interrupt Enable Register” ) in order to configure the parallel capture mode interrupt mask.
2. Write PIO_PCMR (“PIO Parallel Capture Mode Register” ) to set the fields DSIZE, ALWYS, HALFS and FRSTS in
order to configure the parallel capture mode WITHOUT enabling the parallel capture mode.
0x23 0x34 0x450x12 0x56 0x67 0x78 0x89
0x6745_2301
MCK
PIODCCLK
PIODC[7:0]
PIODCEN1
PIODCEN2
DRDY (PIO_PCISR)
RDATA (PIO_PCRHR)
0x01
Read of PIO_PCISR
0x23 0x34 0x450x12 0x56 0x67 0x78 0x89
0x7856_3412
MCK
PIODCCLK
PIODC[7:0]
PIODCEN1
PIODCEN2
DRDY (PIO_PCISR)
RDATA (PIO_PCRHR)
0x01
Read of PIO_PCISR