h8s-2172 Renesas Electronics Corporation., h8s-2172 Datasheet - Page 223

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

After one byte, word, or longword has been transferred, the bus is released. While the bus is
released, at least one CPU bus cycle is initiated.
Normal Transfer Mode (Cycle Steal Mode: Transfer Destination is USB): Figure 7.18 shows
an example of transfer when USB transfer is enabled, and word-size, normal transfer mode (cycle
steal mode) is performed from external 16-bit, 2-state access space to the FIFO in the USB.
After one byte, word, or longword has been transferred, the bus is released. While the bus is
released, at least one CPU bus cycle is initiated.
Block Transfer Mode (Cycle Steal Mode): Figure 7.19 shows an example of transfer when
TEND output is enabled, and word-size, block transfer mode (cycle steal mode) is performed from
external 16-bit, 2-state access space to external 16-bit, 2-state access space.
φ
Address bus
φ
Address bus
USB write
(internal signal)
Figure 7.18 Example of Normal Transfer Mode (Cycle Steal Mode) Transfer
Figure 7.19 Example of Block Transfer Mode (Cycle Steal Mode) Transfer
DMA read DMA write
DMA
External
read
memory
DMA
write
USB
(Transfer Destination: USB)
DMA
read
release
Bus
DMA read DMA write
DMA
write
External
memory
release
Bus
USB
DMA
read
Rev. 2.00, 03/04, page 191 of 534
release
Bus
DMA
write
DMA read DMA write
External
memory
DMA
read
USB
DMA
write