HD6417021 Hitachi Semiconductor, HD6417021 Datasheet - Page 204
HD6417021
Manufacturer Part Number
HD6417021
Description
SuperH RISC engine
Manufacturer
Hitachi Semiconductor
Datasheet
1.HD6417021.pdf
(507 pages)
- Current page: 204 of 507
- Download datasheet (2Mb)
External-Pin Round-Robin Mode: External-pin round-robin mode switches the priority levels of
channel 0 and channel 1, which are the channels that can receive transfer requests from external
pins DREQ0 and DREQ1. The priority levels are changed after each (byte or word) transfer on
channel 0 or channel 1 is completed. The channel which just finished the transfer rotates to the
bottom of the priority order. The priority levels of channels 2 and 3 do not change. The initial
priority order after a reset is channel 3 > channel 2 > channel 1 > channel 0.
Figure 9.5 shows how the priority order changes when channel 0 and channel 1 transfers are
requested simultaneously and a channel 0 transfer is requested again after both channels finish
their transfers. The DMAC operates as follows:
1. Transfer requests are generated simultaneously to channels 1 and 0.
2. Channel 1 has a higher priority, so the channel 1 transfer begins first (channel 0 waits for
3. When the channel 1 transfer ends, channel 1 becomes lowest priority.
4. The channel 0 transfer begins.
5. When the channel 0 transfer ends, channel 0 becomes lowest priority.
6. A channel 0 transfer request occurs again.
7. The channel 0 transfer begins.
8. When the channel 0 transfer ends, the priority order does not change, because channel 0 is
transfer).
already the lowest priority.
HITACHI 189
Related parts for HD6417021
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
HM628128LFP-10Hitachi Semiconductor [131072-word x 8-bit High Speed CMOS Static RAM]
Manufacturer:
HITACHI
Datasheet:
Part Number:
Description:
Silicon N-Channel Junction FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
Part Number:
Description:
Silicon N-Channel MOS FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
Part Number:
Description:
Silicon N-Channel MOS FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
Part Number:
Description:
Silicon N-Channel MOS FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
Part Number:
Description:
Silicon N-Channel MOS FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
Part Number:
Description:
Silicon N-Channel Junction FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
Part Number:
Description:
Silicon N-Channel MOS FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
Part Number:
Description:
Silicon N-Channel MOS FET
Manufacturer:
Hitachi Semiconductor
Datasheet:
Part Number:
Description:
GaAs HEMT
Manufacturer:
Hitachi Semiconductor
Datasheet:
Part Number:
Description:
Silicon N Channel MOS FET High Speed Power Switching
Manufacturer:
Hitachi Semiconductor
Datasheet:
Part Number:
Description:
Silicon N Channel MOS FET High Speed Power Switching
Manufacturer:
Hitachi Semiconductor
Datasheet:
Part Number:
Description:
Silicon N Channel MOS FET Low Frequency Power Switching
Manufacturer:
Hitachi Semiconductor
Datasheet:
Part Number:
Description:
Silicon N Channel MOS FET High Speed Switching
Manufacturer:
Hitachi Semiconductor
Datasheet:
Part Number:
Description:
Silicon N Channel MOS FET High Speed Switching
Manufacturer:
Hitachi Semiconductor
Datasheet: