Renesas M16C Series User Manual

Universal Serial Bus
M30240 Group
Rev.1.00 Sep 24, 2003 Page 59 of 360
1.2.18.4.17 USB Endpoint x OUT MAXP Register
The USB Endpoint x OUT MAXP Register, shown in Figure 1.50, indicates the maximum packet size (MAXP)
of an Endpoint x OUT packet. The default values for endpoints 1-4 are 0 bytes. The setting of this register also
affects the configuration of single/dual packet operation. When MAXP > 1/2 of the FIFO size, single packet is
set. When MAXP <= 1/2 of the FIFO size, dual packet mode is set.
Figure 1.50: USB Endpoint x OUT MAXP
1.2.18.4.18 USB Endpoint x OUT Write Count Register
The USB Endpoint x OUT Write Count (WRT CNT) Register, shown in Figure 1.51, contains the number of
bytes of the current data set in the OUT FIFO. The USB FCU sets the value in the Write Count Register after
having successfully received a packet of data from the host. The CPU reads the register to determine the number
of bytes to be read from the FIFO.
Figure 1.51: USB Endpoint x OUT WRT CNT
1.2.18.4.19 USB Endpoint x FIFO Register
The USB Endpoint x FIFO Register, shown in Figure 1.52 is the USB IN (transmit) and OUT (receive) FIFO
data register. The CPU writes data to this register for the corresponding Endpoint IN FIFO and reads data from
this register for the corresponding Endpoint OUT FIFO.
Figure 1.52: USB Endpoint x FIFO Register
USB Endpoint x OUT MAXP Register
Symbol Address
When reset
EPiOMP (i = 1-4) 031C
16, 0324 16, 032C 16, 0334 16
00
16
Bit nameBit symbol
b7 b6 b5 b4 b3 b2 b1 b0
OMAXP0
to
OMAXP7
Function
WR
Maximum packet size
(MAXP) of Endpoint x
OUT packet.
For endpoints that support smaller
FIFO size, unused bits are not
implemented, (always write "0" to
these bits).
USB Endpoint x OUT Write Count Register
Symbol Address When reset
EPiWC (i = 1-4) 031D
16, 0325 16, 032D 16, 0335 16 00 16
Bit nameBit symbol
b7 b6 b5 b4 b3 b2 b1 b0
W_CNT0
to
W_CNT7
Function
WR
Receive Byte Count
X
USB Endpoint x FIFO Register
Symbol Address When reset
EPi (i = 0-4) 0338
16, 0339 16, 033A 16, 033B 16, 033C 16 Indeterminate
Bit name
Bit symbol
b7 b6 b5 b4 b3 b2 b1 b0
DATA_0
to
DATA_7
Function
WR
Endpoint x IN/OUT FIFO
O

Renesas M16C Series Specifications

General

Brand	Renesas
Model	M16C Series
Category	Computer Hardware
Language	English