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Chain Transfer: An example of DTC chain transfer is shown in which pulse output is performed
using the PPG. Chain transfer can be used to perform pulse output data transfer and PPG output
trigger cycle updating. Repeat mode transfer to the PPG's NDR is performed in the first half of the
chain transfer, and normal mode transfer to the TPU's TGR in the second half. This is because
clearing of the activation source and interrupt generation at the end of the specified number of
transfers are restricted to the second half of the chain transfer (transfer when CHNE = 0).
[1] Perform settings for transfer to the PPG's NDR. Set MRA to source address incrementing
(SM1 = 1, SM0 = 0), fixed destination address (DM1 = DM0 = 0), repeat mode (MD1 = 0,
MD0 = 1), and word size (Sz = 1). Set the source side as a repeat area (DTS = 1). Set MRB to
chain mode (CHNE = 1, DISEL = 0). Set the data table start address in SAR, the NDRH
address in DAR, and the data table size in CRAH and CRAL. CRB can be set to any value.
[2] Perform settings for transfer to the TPU's TGR. Set MRA to source address incrementing
(SM1 = 1, SM0 = 0), fixed destination address (DM1 = DM0 = 0), normal mode (MD1 =
MD0 = 0), and word size (Sz = 1). Set the data table start address in SAR, the TGRA address
in DAR, and the data table size in CRA. CRB can be set to any value.
[3] Locate the TPU transfer register information consecutively after the NDR transfer register
information.
[4] Set the start address of the NDR transfer register information to the DTC vector address.
[5] Set the bit corresponding to TGIA in DTCER to 1.
[6] Set TGRA as an output compare register (output disabled) with TIOR, and enable the TGIA
interrupt with TIER.
[7] Set the initial output value in PODR, and the next output value in NDR. Set bits in DDR and
NDER for which output is to be performed to 1. Using PCR, select the TPU compare match
to be used as the output trigger.
[8] Set the CST bit in TSTR to 1, and start the TCNT count operation.
[9] Each time a TGRA compare match occurs, the next output value is transferred to NDR and
the set value of the next output trigger period is transferred to TGRA. The activation source
TGFA flag is cleared.
[10] When the specified number of transfers are completed (the TPU transfer CRA value is 0), the
TGFA flag is held at 1, the DTCE bit is cleared to 0, and a TGIA interrupt request is sent to
the CPU. Termination processing should be performed in the interrupt handling routine.
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