r4f2456 Renesas Electronics Corporation., r4f2456 Datasheet - Page 476

• Manufacturer Part Number: r4f2456
• Description: 16-bit Single-chip Microcomputer H8s Family / H8s/2400 Series
• Manufacturer: Renesas Electronics Corporation.

Section 8 EXDMA Controller (EXDMAC)
Rev. 1.00 Sep. 19, 2008 Page 446 of 1342
REJ09B0467-0100
φ pin
EDREQ
EDRAK
Bus cycle
CPU
operation
EDACK
ETEND
φ pin
EDREQ
EDRAK
EDREQ
acceptance
internal
processing
state
Bus cycle
EDACK
CPU cycle
Figure 8.36 External Request/Cycle Steal Mode/Normal Transfer Mode
Figure 8.37 External Request/Cycle Steal Mode/Normal Transfer Mode
External
space
(No Contention/Single Address Mode/Falling Edge Sensing)
CPU cycle CPU cycle
External
(CPU Cycles/Single Address Mode/Low Level Sensing)
space
Bus release
Edge confirmation
Start of transfer
processing
External
space
Start of high
level sensing
EXDMA single
transfer cycle
External
EXDMA single
space
transfer cycle
Edge confirmation
Start of transfer
processing
Bus release
CPU cycle CPU cycle
2 bus cycles
EXDMA single
Start of high
level sensing
transfer cycle
External
space
Edge confirmation
Start of transfer
processing
Bus release
Last transfer cycle
External
EXDMA single
space
transfer cycle
Start of high
level sensing
EXDMA single
transfer cycle
CPU cycle