r4f2456 Renesas Electronics Corporation., r4f2456 Datasheet - Page 375

• Manufacturer Part Number: r4f2456
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

Table 7.6
MAR specifies the start address of the transfer source or transfer destination as 24 bits. MAR is
neither incremented nor decremented by a data transfer. IOAR specifies the lower 16 bits of the
other address. The upper 8 bits of IOAR have a value of H'FF.
Figure 7.5 illustrates operation in idle mode.
The number of transfers is specified as 16 bits in ETCR. ETCR is decremented by 1 each time a
transfer is executed, and when its value reaches H'0000, the DTE bit is cleared and data transfer
ends. If the DTIE bit is set to 1 at this time, an interrupt request is sent to the CPU or DTC. The
maximum number of transfers, when H'0000 is set in ETCR, is 65,536.
Transfer requests (activation sources) consist of A/D converter conversion end interrupts, external
requests, SCI transmission complete and reception complete interrupts, and TPU channel 0 to 5
compare match/input capture A interrupts. External requests can only be specified for channel B.
Figure 7.6 shows an example of the setting procedure for idle mode.
Register
23
23
H'FF
15
MAR
15
Register Functions in Idle Mode
ETCR
MAR
IOAR
0
0
0
Figure 7.5 Operation in Idle Mode
DTDIR = 0 DTDIR = 1 Initial Setting
Source
address
register
Destination
address
register
Transfer counter
Function
Destination
address
register
Source
address
register
Transfer
1 byte or word transfer performed in
response to 1 transfer request
Start address of
transfer destination
or transfer source
Start address of
transfer source or
transfer destination
Number of transfers Decremented every
Rev. 1.00 Sep. 19, 2008 Page 345 of 1342
Section 7 DMA Controller (DMAC)
Operation
Fixed
Fixed
transfer; transfer
ends when count
reaches H'0000
REJ09B0467-0100
IOAR