Datasheet

Table Of Contents
Section 7 DMA Controller (DMAC)
REJ09B0140-0900 Rev. 9.00 Page 193 of 846
Sep 16, 2010
H8S/2215 Group
Full Address Mode (Cycle Steal Mode): Figure 7.17 shows a transfer example in which
TEND
*
output is enabled and word-size full address mode transfer (cycle steal mode) is performed
from external 16-bit, 2-state access space to external 16-bit, 2-state access space.
φ
DMA read
RD
HWR
TEND*
LWR
DMA write DMA read DMA write DMA read DMA write
DMA
dead
Address bus
Bus release Bus release Bus release Bus releaseLast transfer cycle
Note: * TEND output cannot be used with this LSI.
Figure 7.17 Example of Full Address Mode (Cycle Steal) Transfer
A one-byte or one-word transfer is performed, and after the transfer the bus is released. While the
bus is released one bus cycle is inserted 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.
Note: * TEND output cannot be used with this LSI.