Rev.2.00 Oct 16, 2006 page 197 of 354
REJ09B0340-0200
M30245 Group
2. USB function
•CLR_UNDER_RUN bit
The UNDER_RUN flag is cleared to “0” by setting “1” to this bit.
•TOGGLE_INIT bit
This bit initializes data toggle bit required in bulk and interrupt transfer.
When initialization of the data toggle sequence is requested from the host CPU at the time of configu-
ration, etc., set this bit to “1” before starting the IN endpoint communication and initialize PID to
DATA0. At this time, the internal read/write pointer of IN FIFO is also initialized.
•FLUSH bit
This bit controls the IN FIFO packet.
Read the IN_BUF_STS1 and IN_BUF_STS0 flags and confirm that there are data in the IN FIFO,
and then, set this bit to “1”. When the IN FIFO is flushed, the IN_BUF_STS1 and IN_BUF_STS0 flags
are updated as follows:
- When there is one buffer data in IN FIFO, the IN FIFO becomes empty.
At this time, the IN_BUF_STS1 and IN_BUF_STS0 flags are updated to “00
2
”.
- When two buffer data exist in IN FIFO, the older data is flushed.
At this time, the IN_BUF_STS1 and IN_BUF_STS0 flags are updated to “01
2
”. (This indicates that
one more buffer data is left inside the IN FIFO.)
The transmit data may be destroyed if this bit is set to “1” during USB transfer.
On completing one buffer data flush, this bit is automatically cleared to “0”.
•INTPT bit
This bit controls transfer mode in interrupt transfer. Only when using the IN endpoint for the rate
feedback interrupt transfer, set this bit to “1”.
With this bit being set to “1”, when an IN token is received from the host CPU, IN FIFO data are
transmitted regardless of the IN_BUF_STS1 and IN_BUF_STS0 flag states or the data toggle.
Fix this bit at “0” for isochronous transfer, bulk transfer, and normal interrupt transfer.
•ISO bit
This bit controls isochronous transfer. With this bit being set to “1”, the IN endpoint is used for isoch-
ronous transfer. Fix this bit at “0” for bulk transfer and interrupt transfer.
•SEND_STALL bit
This bit controls the STALL response to the host CPU.
Set this bit to “1” when the IN endpoint is in STALL state. While this bit is set to “1”, the USB function
control unit transmits the STALL handshake concerning all the IN transactions to the host CPU.
When the IN endpoint has returned from STALL state, write “0” to clear this bit. The IN endpoint
communication is resumed.
Содержание M16C FAMILY
Страница 12: ...Chapter 1 Hardware...
Страница 13: ...See M30245 group datasheet...
Страница 14: ...Chapter 2 Peripheral Functions Usage...
Страница 303: ...THIS PAGE IS BLANK FOR REASONS OF LAYOUT...
Страница 304: ...Chapter 3 Examples of Peripheral Functions Applications...
Страница 340: ...Chapter 4 External Buses...
Страница 361: ...THIS PAGE IS BLANK FOR REASONS OF LAYOUT...
Страница 362: ...Chapter 5 Standard Characteristics...
Страница 369: ...1753 Shimonumabe Nakahara ku Kawasaki shi Kanagawa 211 8668 Japan M30245 Group REJ09B0340 0200 User s Manual...