Datasheet

263
11.3.11 Source Address Reload Function
Channel 2 has a source address reload function. This returns to the first value set in the source
address register (SAR2) every four transfers by setting the RO bit of CHCR2 to 1. Figure 11.25
illustrates this operation. Figure 11.26 is a timing chart for reload ON mode, with burst mode,
autorequest, 16-bit transfer data size, SAR2 increment, and DAR2 fixed mode.
SAR2
(initial value)
DMAC
Transfer
request
DMAC control block
Reload control
4th count
CHCR2
DMATCR2
SAR2
RO bit = 1
Count signal
Reload 
signal
Reload signal
Address bus
Figure 11.25 Source Address Reload Function
CK
Internal
address bus
Internal
data bus
SAR2 DAR2 DAR2 DAR2 DAR2SAR2+2 SAR2+4 SAR2+6 SAR2 DAR2
SAR2 data SAR2+2 data SAR2+4 data SAR2+6 data SAR2 data
1st channel 2
transfer
2nd channel 2
transfer
3rd channel 2
transfer
4th channel 2
transfer
5th channel 2
transfer
SAR2 output
DAR2 output
SAR2+2 output
DAR2 output
SAR2+4 output
DAR2 output
SAR2+6 output
DAR2 output
SAR2 output
DAR2 output
After SAR2+6 output, SAR2 is reloaded Bus right is returned one time in four
Figure 11.26 Source Address Reload Function Timing Chart