HD6412373R RENESAS [Renesas Technology Corp], HD6412373R Datasheet - Page 400

• Manufacturer Part Number: HD6412373R
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family/H8S/2300 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 7 DMA Controller (DMAC)
7.5.9
Short Address Mode: Figure 7.18 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 byte or word transfer is performed for a single 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 end cycle.
Rev.7.00 Mar. 18, 2009 page 332 of 1136
REJ09B0109-0700
Address bus
TEND
HWR
LWR
RD
DMA Transfer (Dual Address Mode) Bus Cycles
Bus release
φ
Figure 7.18 Example of Short Address Mode Transfer
DMA
read
DMA
write
Bus release
DMA
read
DMA
write
Bus release
DMA
read
Last transfer
cycle
DMA
write
DMA
dead
Bus
release