USB on-the-go full-speed (OTG_FS) RM0033
1018/1381 RM0033 Rev 9
OTG_FS Host channel-x transfer size register (OTG_FS_HCTSIZx) (x = 0..7,
where x = Channel_number)
Address offset: 0x510 + 0x20 * x
Reset value: 0x0000 0000
Bit 2 Reserved, must be kept at reset value.
Bit 1 CHHM: Channel halted mask
0: Masked interrupt
1: Unmasked interrupt
Bit 0 XFRCM: Transfer completed mask
0: Masked interrupt
1: Unmasked interrupt
313029282726252423222120191817161514131211109876543210
Reserved
DPID PKTCNT XFRSIZ
rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw rw
Bit 31 Reserved, must be kept at reset value.
Bits 30:29 DPID: Data PID
The application programs this field with the type of PID to use for the initial transaction. The
host maintains this field for the rest of the transfer.
00: DATA0
01: DATA2
10: DATA1
11: MDATA (non-control)/SETUP (control)
Bits 28:19 PKTCNT: Packet count
This field is programmed by the application with the expected number of packets to be
transmitted (OUT) or received (IN).
The host decrements this count on every successful transmission or reception of an OUT/IN
packet. Once this count reaches zero, the application is interrupted to indicate normal
completion.
Bits 18:0 XFRSIZ: Transfer size
For an OUT, this field is the number of data bytes the host sends during the transfer.
For an IN, this field is the buffer size that the application has reserved for the transfer. The
application is expected to program this field as an integer multiple of the maximum packet
size for IN transactions (periodic and non-periodic).