Example Of Normal Pulse Output (Example Of Five-Phase Pulse Output); Figure 12.5 Normal Pulse Output Example (Five-Phase Pulse Output) - Hitachi H8S/2628 Hardware Manual

12.4.4

Example of Normal Pulse Output (Example of Five-Phase Pulse Output)

Figure 12.5 shows an example in which pulse output is used for cyclic five-phase pulse output.
TCNT value
TCNT
TGRA
H'0000
80 C0
NDRH
80
PODRH 00
PO15
PO14
PO13
PO12
PO11

Figure 12.5 Normal Pulse Output Example (Five-Phase Pulse Output)

1. Set up TGRA of the TPU that is used as the output trigger to be an output compare register.
Set a frequency in TGRA so the counter will be cleared on compare match A. Set the TGIEA
bit of TIER to 1 to enable the compare match/input capture A (TGIA) interrupt.
2. Write H'F8 in P1DDR and NDERH, and set the G3CMS0, G3CMS1, G2CMS0, and G2CMS1
bits in PCR to select compare match in the TPU channel set up in the previous step to be the
output trigger. Write output data H'80 in NDRH.
3. When compare match A occurs, the NDRH contents are transferred to PODRH and output.
The TGIA interrupt handling routine writes the next output data (H'C0) in NDRH.
4. Five-phase overlapping pulse output (one or two phases active at a time) can be obtained
subsequently by writing H'40, H'60, H'20, H'30. H'10, H'18, H'08, H'88... at successive TGIA
interrupts. If the DTC is set for activation by this interrupt, pulse output can be obtained
without imposing a load on the CPU.
Compare match
40 60 20 30
C0 40 60 20
10 18 08 88
30 10 18 08
Rev. 1.0, 09/02, page 275 of 568
Time
80 C0 40
80
88 C0