How-To Guide

Table Of Contents
R01UH0823EJ0110 Rev.1.10 Page 909 of 1852
Nov 30, 2020
RX23W Group 32. USB 2.0 Host/Function Module (USBc)
BSTS Flag (Buffer Status Flag)
Indicates the FIFO buffer status for the relevant pipe.
The meaning of the BSTS flag depends on the settings of the PIPECFG.DIR bit, PIPECFG.BFRE bit, and
DnFIFOSEL.DCLRM bits as shown in
Table 32.9.
Table 32.6 Operation of USB depending on PID[1:0] Bits Setting (When Host Controller is Selected)
PID[1:0] Bits Transfer Type
Transfer Direction
(DIR Bit) Operation of USB
00b (NAK) Operation does not
depend on the
setting.
Operation does not
depend on the setting.
Does not issue tokens.
01b (BUF) Bulk or interrupt Operation does not
depend on the setting.
Issues tokens while the DVSTCTR0.UACT bit is 1 and the FIFO
buffer corresponding to the relevant pipe is ready for transmission
and reception.
Does not issue tokens while the DVSTCTR0.UACT bit is 0 or the
FIFO buffer corresponding to the relevant pipe is not ready for
transmission or reception.
Isochronous Operation does not
depend on the setting.
Issues tokens irrespective of the status of the FIFO buffer
corresponding to the relevant pipe.
10b (STALL) or
11b (STALL)
Operation does not
depend on the
setting.
Operation does not
depend on the setting.
Does not issue tokens.
Table 32.7 Operation of USB depending on PID[1:0] Bits Setting (When Function Controller is Selected)
PID[1:0] Bits Transfer Type
Transfer Direction
(DIR Bit) Operation of USB
00b (NAK) Bulk or interrupt Operation does not
depend on the setting.
Returns NAK in response to the token from the USB host.
Isochronous Operation does not
depend on the setting.
Returns nothing in response to the token from the USB host.
01b (BUF) Bulk Receiving direction
(DIR bit = 0)
Receives data and returns ACK in response to the OUT token from
the USB host if the FIFO buffer corresponding to the relevant pipe is
ready for reception.
Interrupt Receiving direction
(DIR bit = 0)
Receives data and returns ACK in response to the OUT token from
the USB host if the FIFO buffer corresponding to the relevant pipe is
ready for reception.
Bulk or interrupt Transmitting direction
(DIR bit = 1)
Transmits data in response to the token from the USB host if the
corresponding FIFO buffer is ready for transmission. Returns NAK if
not ready.
Isochronous Receiving direction
(DIR bit = 0)
Receives data in response to the OUT token from the USB host if the
FIFO buffer corresponding to the relevant pipe is ready for reception.
Discards data if not ready.
Isochronous Transmitting direction
(DIR bit = 1)
Transmits data in response to the token from the USB host if the
corresponding FIFO buffer is ready for transmission. Transmits the
zero-length packet if not ready.
10b (STALL) or
11b (STALL)
Bulk or interrupt Operation does not
depend on the setting.
Returns STALL in response to the token from the USB host.
Isochronous Operation does not
depend on the setting.
Returns nothing in response to the token from the USB host.