HD6432670 Hitachi, HD6432670 Datasheet - Page 332

• Manufacturer Part Number: HD6432670
• Description: (HD64F267x Series) 16-Bit Microcomputer
• Manufacturer: Hitachi

7.5.2
Sequential mode can be specified by clearing the RPE bit in DMACR to 0. In sequential mode,
MAR is updated after each byte or word transfer in response to a single transfer request, and this is
executed the number of times specified in ETCR. One address is specified by MAR, and the other
by IOAR. The transfer direction can be specified by the DTDIR bit in DMACR.
Table 7.5 summarizes register functions in sequential mode.
Table 7.5
Register
MAR specifies the start address of the transfer source or transfer destination as 24 bits. MAR is
incremented or decremented by 1 or 2 each time a byte or word is transferred. IOAR specifies the
lower 16 bits of the other address. The 8 bits above IOAR have a value of H'FF.
Figure 7.3 illustrates operation in sequential mode.
Rev. 2.0, 04/02, page 286 of 906
23
23
H'FF
15
Sequential Mode
15
Register Functions in Sequential Mode
ETCR
MAR
IOAR
0
0
0
DTDIR = 0 DTDIR = 1 Initial Setting
Source
address
register
Destination
address
register
Transfer counter
Function
Destination
address
register
Source
address
register
Start address of
transfer destination
or transfer source
Start address of
transfer source or
transfer destination
Number of transfers Decremented every
Operation
Incremented/
decremented every
transfer
Fixed
transfer; transfer
ends when count
reaches H'0000