Datasheet

Section 9 Data Transfer Controller (DTC)
Rev. 6.00 Mar. 18, 2010 Page 302 of 982
REJ09B0054-0600
9.7 Examples of Use of the DTC
9.7.1 Normal Mode
An example is shown in which the DTC is used to receive 128 bytes of data via the SCI.
1. Set MRA to a fixed source address (SM1 = SM0 = 0), incrementing destination address
(DM1 = 1, DM0 = 0), normal mode (MD1 = MD0 = 0), and byte size (Sz = 0). The DTS bit
can have any value. Set MRB for one data transfer by one interrupt (CHNE = 0, DISEL = 0).
Set the 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.
9.7.2 Software Activation
An example is shown in which the DTC is used to transfer a block of 128 bytes of data by means
of software activation. The transfer source address is H'1000 and the destination address is
H'2000. The vector number is H'60, so the vector address is H'04C0.
1. Set MRA to incrementing source address (SM1 = 1, SM0 = 0), incrementing destination
address (DM1 = 1, DM0 = 0), block transfer mode (MD1 = 1, MD0 = 0), and byte size (Sz =
0). The DTS bit can have any value. Set MRB for one block transfer by one interrupt (CHNE
= 0). Set the transfer source address (H'1000) in SAR, the destination address (H'2000) in
DAR, and 128 (H'8080) in CRA. Set 1 (H'0001) in CRB.
2. Set the start address of the register information at the DTC vector address (H'04C0).
3. Check that the SWDTE bit in DTVECR is 0. Check that there is currently no transfer
activated by software.