ST STM32F101 series Reference Manual page 641

Universal serial bus full-speed device interface (USB)
Transmission byte count n (USB_COUNTn_TX)
Address offset: [USB_BTABLE] + n*16 + 4
USB local Address: [USB_BTABLE] + n*8 + 2
15 14 13
Reserved
Bits 15:10 These bits are not used since packet size is limited by USB specifications to 1023 bytes. Their
value is not considered by the USB peripheral.
Bits 9:0 COUNTn_TX[9:0]: Transmission byte count
These bits contain the number of bytes to be transmitted by the endpoint associated with the
USB_EPnR register at the next IN token addressed to it.
Note: Double-buffered and Isochronous IN Endpoints have two USB_COUNTn_TX registers:
named USB_COUNTn_TX_1 and USB_COUNTn_TX_0 with the following content.
31 30 29
Reserved
15 14 13
Reserved
Reception buffer address n (USB_ADDRn_RX)
Address offset: [USB_BTABLE] + n*16 + 8
USB local Address: [USB_BTABLE] + n*8 + 4
15 14 13
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Bits 15:1 ADDRn_RX[15:1]: Reception buffer address
Bit 0 This bit must always be written as '0 since packet memory is word-wide and all packet buffers
must be word-aligned.
641/1128
12 11 10 9
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28 27 26 25
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12 11 10 9
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12 11 10 9
ADDRn_RX[15:1]
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These bits point to the starting address of the packet buffer, which will contain the data
received by the endpoint associated with the USB_EPnR register at the next OUT/SETUP
token addressed to it.
8 7 6
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24 23 22
COUNTn_TX_1[9:0]
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8 7 6
COUNTn_TX_0[9:0]
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8 7 6
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DocID13902 Rev 15
5 4 3 2
COUNTn_TX[9:0]
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21 20 19 18
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5 4 3 2
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5 4 3
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RM0008
1 0
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17 16
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1 0
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2 1 0
-
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