h8s-2172 Renesas Electronics Corporation., h8s-2172 Datasheet - Page 213

• Manufacturer Part Number: h8s-2172
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family H8s-2100 Series
• Manufacturer: Renesas Electronics Corporation.

Caution is required when the repeat area overflow interrupt function is used together with block
transfer mode. If transfer is always terminated when repeat area overflow occurs in block transfer
mode, the block size must be a power of two, or alternatively, the address register value must be
set so that the end of a block coincides with the end of the repeat area range.
If repeat area overflow occurs while a block is being transferred in block transfer mode, the repeat
interrupt request is held pending until the end of the block, and transfer overrun will occur. Figure
7.10 shows an example in which block transfer mode is used together with the repeat area
function.
When lower 3 bits (8-byte area) of DMSAR are designated as repeat area (SARA4 to SARA0 = 3),
and block size of 5 (DMTCR[23–16] = 5) is set in block transfer mode
External memory
Figure 7.10 Example of Repeat Area Function Operation in Block Transfer Mode
H'23FFFE
H'23FFFF
H'240000
H'240001
H'240002
H'240003
H'240004
H'240005
H'240006
H'240007
H'240008
H'240009
:
:
DMSAR values
H'240000
H'240001
H'240002
H'240003
H'240004
H'240005
H'240006
H'240007
Range of
First block
H'240000
H'240001
H'240002
H'240003
H'240004
transfer
Second block
Rev. 2.00, 03/04, page 181 of 534
H'240000
H'240001
H'240005
H'240006
H'240007
transfer
Block transfer
in progress
Interrupt
requested