BL702/704/706 Reference Manual
6. 0x40000228[20]usb_enum is set to 1, so that the host recognizes that the USB device is inserted and triggers the
enumeration process
18.3.2 Part of the register configuration and function description
• swrdy:Read only, only when this bit is 0, can write 1 to cr_usb_ep0_sw_rdy
• crsr:Writing 1 is automatically cleared. When the software allows the next packet to reply with ACK, write 1 to this
field, and only the next packet will reply with ACK. For OUT/IN transaction data, it will be received or sent from
FIFO (FIFO release once)
• e0snko:It needs to be set to 1, which means that the OUT transaction will reply NAK by default, and the data will
not enter the FIFO (FIFO is not released)
• e0snki:It needs to be set to 1, which means that the IN transaction will reply NAK by default, and the data will not
be sent from the FIFO (FIFO is not released)
• e0ss:Writing 1 is automatically cleared. Write 1 to this field when the software allows the next packet to reply
STALL, then only the next packet will reply STALL
• epxdit:”Token package => trigger xxx_cmd_int => data package => trigger xxx_done_int => handshake package”
• epxcit:”Token package => trigger xxx_cmd_int => data package => trigger xxx_done_int => handshake package”
• ep0odit:”Token package => trigger xxx_cmd_int => data package => trigger xxx_done_int => handshake package”
• ep0ocit:”Token package => trigger xxx_cmd_int => data package => trigger xxx_done_int => handshake package”
• ep0idit:”Token package => trigger xxx_cmd_int => data package => trigger xxx_done_int => handshake package”
• ep0icit:”Token package => trigger xxx_cmd_int => data package => trigger xxx_done_int => handshake package”
• ep0sdit:”Token package => trigger xxx_cmd_int => data package => trigger xxx_done_int => handshake package”
• ep0scit:”Token package => trigger xxx_cmd_int => data package => trigger xxx_done_int => handshake package”
• exrs:Read only. Only when this bit is 0, can write 1 to cr_epx_rdy
• exr:Writing 1 is automatically cleared. When the software allows the next packet to reply ACK, write 1 to this field,
then only the next packet will reply ACK (FIFO release once)
• exn:It needs to be set to 1, which means that the transaction will reply NAK by default. IN/OUT depends on the
transmission direction configuration of the current endpoint (FIFO is not released)
• exs:Set when the software wants to suspend this endpoint, after setting this endpoint will always reply STALL
BL702/704/706 Reference Manual 309/ 375
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