How-To Guide

Table Of Contents
R01UH0823EJ0110 Rev.1.10 Page 875 of 1852
Nov 30, 2020
RX23W Group 32. USB 2.0 Host/Function Module (USBc)
32.2.6 CFIFO Port Control Register (CFIFOCTR),
D0FIFO Port Control Register (D0FIFOCTR),
D1FIFO Port Control Register (D1FIFOCTR)
Note 1. Only 0 can be read.
Registers CFIFOCTR, D0FIFOCTR, and D1FIFOCTR correspond to CFIFO, D0FIFO, and D1FIFO, respectively.
DTLN[8:0] Flags (Receive Data Length Flag)
The DTLN[8:0] flags indicate the length of the receive data.
While the FIFO buffer is being read, the DTLN[8:0] flags indicate different values depending on the DnFIFOSEL.RCNT
bit (n = 0, 1) value as described below.
RCNT = 0
The USB sets the DTLN[8:0] flags to indicate the length of the receive data until the CPU or DMAC/DTC has read
all the received data from a single FIFO buffer plane.
While the PIPECFG.BFRE bit = 1, these bits retain the length of the receive data until the BCLR bit is set to 1 even
after all the data has been read.
RCNT = 1
The USB decrements the value indicated by the DTLN[8:0] flags each time data is read from the FIFO buffer. (The
value is decremented by one when the MBW bit is 0, and by two when the MBW bit is 1.)
The USB sets these bits to 0 when all the data has been read from one FIFO buffer plane. However, in double buffer
mode, if data has been received in one FIFO buffer plane before all the data has been read from the other plane, the
USB sets these bits to indicate the length of the receive data in the former plane when all the data has been read from
the latter plane.
Address(es): USB0.CFIFOCTR 000A 0022h, USB0.D0FIFOCTR 000A 002Ah, USB0.D1FIFOCTR 000A 002Eh
b15 b14 b13 b12 b11 b10 b9 b8 b7 b6 b5 b4 b3 b2 b1 b0
BVAL BCLR FRDY DTLN[8:0]
Value after reset:
0000000000000000
Bit Symbol Bit Name Description R/W
b8 to b0 DTLN[8:0] Receive Data Length Flag Indicate the length of the receive data. These bits indicate different
values depending on the setting of the RCNT bit in the port select
register. For details, refer to the description on the DTLN[8:0] flags
shown below.
R
b12 to b9 Reserved These bits are read as 0. The write value should be 0. R/W
b13 FRDY FIFO Port Ready Flag 0: FIFO port access is disabled.
1: FIFO port access is enabled.
R
b14 BCLR CPU Buffer Clear 0: Does not operate.
1: Clears the buffer memory on the CPU side.
R/W
*1
b15 BVAL Buffer Memory Valid 0: Invalid
1: Writing ended
R/W