Chain Transfer - Renesas H8S Series Hardware Manual

Section 8 Data Transfer Controller (DTC)
SCI RDR address in SAR, the start address of the RAM area where the data will be received in
DAR, and 128 (H'0080) in CRA. CRB can be set to any value.
2. Set the start address of the register information at the DTC vector address.
3. Set the corresponding bit in DTCER to 1.
4. Set the SCI to the appropriate receive mode. Set the RIE bit in SCR to 1 to enable the reception
complete (RXI) interrupt. Since the generation of a receive error during the SCI reception
operation will disable subsequent reception, the CPU should be enabled to accept receive error
interrupts.
5. Each time the reception of one byte of data has been completed on the SCI, the RDRF flag in
SSR is set to 1, an RXI interrupt is generated, and the DTC is activated. The receive data is
transferred from RDR to RAM by the DTC. DAR is incremented and CRA is decremented.
The RDRF flag is automatically cleared to 0.
6. When CRA becomes 0 after the 128 data transfers have been completed, the RDRF flag is held
at 1, the DTCE bit is cleared to 0, and an RXI interrupt request is sent to the CPU. The
interrupt handling routine will perform wrap-up processing.
8.7.2

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 incrementing source address
(SM1 = 1, SM0 = 0), a 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 incrementing source address
(SM1 = 1, SM0 = 0), a 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.
Rev. 6.00 Mar 15, 2006 page 124 of 570
REJ09B0211-0600