HD6412320 RENESAS [Renesas Technology Corp], HD6412320 Datasheet - Page 313

• Manufacturer Part Number: HD6412320
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family H8S-2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

7.5.10
Short Address Mode: Figure 7.19 shows a transfer example in which TEND output is enabled
and byte-size short address mode transfer (sequential/idle/repeat mode) is performed from external
8-bit, 2-state access space to internal I/O space.
A one-byte or one-word transfer is performed for one transfer request, and after the transfer the
bus is released. While the bus is released one or more bus cycles are executed by the CPU or DTC.
In the transfer end cycle (the cycle in which the transfer counter reaches 0), a one-state DMA dead
cycle is inserted after the DMA write cycle.
In repeat mode, when TEND output is enabled, TEND output goes low in the transfer cycle in
which the transfer counter reaches 0.
Address bus
TEND
HWR
LWR
RD
DMAC Bus Cycles (Dual Address Mode)
φ
Bus release
Figure 7.19 Example of Short Address Mode Transfer
DMA
read
DMA
write
Bus release
Section 7 DMA Controller (Not Supported in the H8S/2321)
DMA
read
DMA
write
Rev.6.00 Sep. 27, 2007 Page 283 of 1268
Bus release
DMA
read
Last transfer
cycle
DMA
write
REJ09B0220-0600
DMA
dead
Bus
release