Renesas M30245 Series User Manual page 217

M30245 Group
(6) USB Transmit (Endpoints 1 to 4 IN): Example
The endpoints 1 to 4 IN transmit packet prepare routine (continuous transfer disable) is shown in
Figure 2.8.49. In addition to packet prepare process, error process by the UNDER_RUN flag is re-
quired in isochronous transfer.
1. Confirming of whether there is a space which is equal to one packet in the IN FIFO:
check the IN_BUF_STS0 and the IN_BUF_STS1.
(b15)
b7
0 0 0 0
IN FIFO full
2. Writing of the transmit data equal to one packet data (Note 1) to the IN FIFO.
(b15)
b7
Note 1: The packet data is one buffer data in continuous transfer mode.
3. Setting of the SET_IN_BUF_RDY bit to "1" and completion of one packet data (Note 2) prepare.
(b15)
b7
0 0 0 0 0
Note 2: The packet data is one buffer data in continuous transfer mode.
Note 3: When the AUTO_SET bit is set to "1", this bit is automatically set to "1" when the data count set by
maximum packet size register is written to the IN FIFO. When the AUTO_SET bit is set to "0" or the
AUTO_SET bit is set to "1" and it is a short packet (data packet which is smaller than maximum packet size),
this bit is set to "1" by software.
Figure 2.8.49. Endpoint 1 to 4 IN packet prepare routine
Rev.2.00 Oct 16, 2006
REJ09B0340-0200
Process of USB endpoint x IN packet prepare
(b8)
b0 b7
0
(b8)
b0 b7
Setting of the transmit data
(b8)
b0 b7
0
Execution of the above 2 and 3 again when the second
packet data is set on the double buffer mode.
Completion of packet data prepare
page 206 of 354
b0
USB endpoint x IN control and status register
EPxICS (x = 1 - 4) [Address 029E
IN_BUF_STS0 flag
IN_BUF_STS1 flag
b1 b0
0 0 : No data set in the IN buffer
0 1 : Single buffer mode: N/A
Double buffer mode: one data set in the IN buffer
1 0 : N/A
1 1 : Single buffer mode: one data set in the IN buffer
Double buffer mode: two data set in the IN buffer
There is a space in the IN FIFO.
b0
USB endpoint x IN FIFO data register
EPxI (x = 0 - 4) [Address 02E0
b0
USB endpoint x IN control and status register
EPxICS (x = 1 - 4) [Address 029E
SET_IN_BUF_RDY bit
1 : Transmission data set loaded to the IN buffer
(updates IN_BUF_STS0, IN_BUF_STS1 flags)
2. USB function
, 02A4 , 02AA , 02B0
16 16 16
, 02E4 , 02E8 , 02EC , 02F0
16 16 16 16
, 02A4 , 02AA , 02B0
16 16 16
]
16
]
16
]
16