h8s-2172 Renesas Electronics Corporation., h8s-2172 Datasheet - Page 202

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

Rev. 2.00, 03/04, page 170 of 534
Bit
12
11
10
9
8 to 0
Bit Name

EP2DMAE
UWCHS1
UWCHS0

Initial
Value
0
0
0
0
All 0
R/W
R/W
R/W
R/W
R/W
R/W
Description
Reserved
This bit can be read from or written to. However, the
write value should always be 0.
Endpoint 2 (EP2) DMA Enable
Enables a transfer source from the on-chip USB
(transfer direction: writing to the on-chip USB). When
this bit is set to 1, a transfer request from the USB is
selected as a transfer source.
In block transfer mode, the on-chip USB request must
not be set as an activation source. While the DA bit in
DMMDR is set to 1, the EP2DMAE value must not be
changed.
0: Transfer request from on-chip USB (EP2) not
1: Transfer request from on-chip USB (EP2) accepted.
USB Write Channel Select
When the DMA transfer is performed by a transfer
request from the USB (EP2), these bits select the
DMAC channel to be used. When the channel which
accepts a request is selected and the EP2DMAE bit is
set to 1, the corresponding channel accepts a USB
request rather than an external request. In this case,
the transfer direction is writing to the on-chip USB
(EP2). Therefore, the destination address must be
specified as the FIFO in the on-chip USB (EP2).
While the DA bit in DMMDR is set to 1, these bits must
not be changed. A transfer request from the endpoint 1
(EP1) (reading from the on-chip USB) or a transfer
request from the endpoint 2 (EP2) (writing to the on-
chip USB) must not be set to the same channel.
00: Channel 0 can accept the EP2 transfer request.
01: Channel 1 can accept the EP2 transfer request.
10: Channel 2 can accept the EP2 transfer request.
11: Channel 3 can accept the EP2 transfer request.
Reserved
These bits can be read from or written to. However, the
write value should always be 0.
The DREQ pin on the corresponding channel is not
available.
accepted.