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Section 20 USB Function Module
Rev. 4.00 Sep. 14, 2005 Page 776 of 982
REJ09B0023-0400
20.4.5
EP2 Bulk-IN Transfer (Dual FIFOs)
EP2 has two 64-byte FIFOs, but the user can perform data transmission and transmit data writes
without being aware of this dual-FIFO configuration. However, one data write is performed for
one FIFO. For example, even if both FIFOs are empty, it is not possible to perform EP2/PKTE at
one time after consecutively writing 128 bytes of data. EP2/PKTE must be performed for each 64-
byte write.
When performing bulk-IN transfer, as there is no valid data in the FIFOs on reception of the first
IN token, a USBIFR0/EP2 TR interrupt is requested. With this interrupt, 1 is written to the
USBIER0/EP2EMPTY bit, and the EP2 FIFO empty interrupt is enabled. At first, both EP2 FIFOs
are empty, and so an EP2 FIFO empty interrupt is generated immediately.
The data to be transmitted is written to the data register using this interrupt. After the first transmit
data write for one FIFO, the other FIFO is empty, and so the next transmit data can be written to
the other FIFO immediately. When both FIFOs are full, EP2EMPTY is cleared to 0. If at least one
FIFO is empty, USBIFR0/EP2EMPTY is set to 1. When ACK is returned from the host after data
transmission is completed, the FIFO used in the data transmission becomes empty. If the other
FIFO contains valid transmit data at this time, transmission can be continued.
When transmission of all data has been completed, write 0 to USBIER0/EP2EMPTY and disable
interrupt requests.
Содержание HD6417641
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Страница 11: ...Rev 4 00 Sep 14 2005 Page xi of l USB Universal serial bus WDT Watch dog timer...
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Страница 204: ...Section 4 Clock Pulse Generator CPG Rev 4 00 Sep 14 2005 Page 154 of 982 REJ09B0023 0400...
Страница 212: ...Section 5 Watchdog Timer WDT Rev 4 00 Sep 14 2005 Page 162 of 982 REJ09B0023 0400...
Страница 228: ...Section 6 Power Down Modes Rev 4 00 Sep 14 2005 Page 178 of 982 REJ09B0023 0400...
Страница 246: ...Section 8 X Y Memory Rev 4 00 Sep 14 2005 Page 196 of 982 REJ09B0023 0400...
Страница 318: ...Section 11 User Break Controller UBC Rev 4 00 Sep 14 2005 Page 268 of 982 REJ09B0023 0400...
Страница 454: ...Section 12 Bus State Controller BSC Rev 4 00 Sep 14 2005 Page 404 of 982 REJ09B0023 0400...
Страница 500: ...Section 13 Direct Memory Access Controller DMAC Rev 4 00 Sep 14 2005 Page 450 of 982 REJ09B0023 0400...
Страница 504: ...Section 14 U Memory Rev 4 00 Sep 14 2005 Page 454 of 982 REJ09B0023 0400...
Страница 566: ...Section 17 Compare Match Timer CMT Rev 4 00 Sep 14 2005 Page 516 of 982 REJ09B0023 0400...
Страница 734: ...Section 18 Multi Function Timer Pulse Unit MTU Rev 4 00 Sep 14 2005 Page 684 of 982 REJ09B0023 0400...
Страница 868: ...Section 21 A D Converter Rev 4 00 Sep 14 2005 Page 818 of 982 REJ09B0023 0400...
Страница 914: ...Section 23 I O Ports Rev 4 00 Sep 14 2005 Page 864 of 982 REJ09B0023 0400...
Страница 956: ...Section 24 List of Registers Rev 4 00 Sep 14 2005 Page 906 of 982 REJ09B0023 0400...
Страница 1016: ...Section 25 Electrical Characteristics Rev 4 00 Sep 14 2005 Page 966 of 982 REJ09B0023 0400...
Страница 1024: ...Appendix Rev 4 00 Sep 14 2005 Page 974 of 982 REJ09B0023 0400...
Страница 1032: ...Rev 4 00 Sep 14 2005 Page 982 of 982 REJ09B0023 0400 X X Y data addressing 52 X Y memory 193...
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