h8s-2172 Renesas Electronics Corporation., h8s-2172 Datasheet - Page 385

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

12.5.6
Note:
This flowchart shows just one example of interrupt-in transfer processing. Other possibilities include an
operation flow in which, if there is data to be transmitted, the EP3DE bit in DASTS0 is referred to confirm that
the FIFO is empty, and then data is written to the FIFO.
EP3 Interrupt-In Transfer
(EP3 TS in IFR0 = 1)
Transmit data to host
Receive IN token
Set EP3 transmit
in EP3 FIFO?
USB function
complete flag
Figure 12.12 EP3 Interrupt-In Transfer Operation
Valid data
Yes
ACK
No
NAK
Interrupt generated
data bytes to packet enable
data bytes to packet enable
Write number of transmit
Write number of transmit
Write data to EP3 data
data register (EPDR3)
(EP3 TS in IFR0 = 0)
register 3 (PKTE3)
Clear EP3 transmit
register 3 (PKTE3)
Write data to EP3
register (EPDR3)
to be transmitted
Is there any data
Is there any data
to be transmitted
complete flag
Rev. 2.00, 03/04, page 353 of 534
to host?
to host?
Firmware
Yes
Yes
No
No