Renesas M16C Series User Manual

Universal Serial Bus
M30240 Group
Rev.1.00 Sep 24, 2003 Page 304 of 360
3.2.2.12 USB Endpoint 0 MaxP Register
The USB Endpoint 0 MaxP Register indicates the Maximum Packet size (MaxP) of Endpoint 0 (IN/
OUT). This register should be updated when the transmission of the SET_DESCRIPTOR command
is received from the host CPU.
Figure 3.18 shows the structure of USB Endpoint 0 MaxP register.
Figure 3.18: USB Endpoint 0 MaxP Register (EP0MP)
3.2.2.13 USB Endpoint 0 OUT Write Count Register
This is the 5-bit register that contains the number of bytes of data written to the endpoint 0 OUT FIFO.
The USB FCU sets the value in the write count register after successfully receiving a data packet from
the host. This register should be referenced when data is read from the OUT FIFO.
Figure 3.19 shows the structure of the USB Endpoint 0 OUT Write Count Register.
Figure 3.19: USB 0 OUT Write Counter Register
3.2.2.14 USB Endpoint X IN Control/Status Register
• The USB Endpoint X IN Control and Status Register contains the control and status information for the
specific IN Endpoint (1-4).
• IN_PKT_RDY Bit
This bit is set to “1” when a data packet is written to the IN FIFO. If AUTO_SET = 1, it automatically
becomes “1” when the MaxP is written to the FIFO. After the transmission of the data packet from the
IN FIFO has ended (after the receipt of the ACK transmission from the host), the USB function control
unit clears this bit to “0”.
The IN_PKT_RDY bit is used to confirm the end of the transmission of the data packet. The state of
this bit should be confirmed with the TX_NOT_EPT flag.
Bit Symbol Bit Name Function R W
EP0MXP0 to
EP0MXP5
Reserved
Maximum packet size (MaxP)
of Endpoing 0 IN/OUT packet
Must always be set to "0"
O O
O O
O O
Symbol
EP0MP
Address
0313
16
When reset
08
16
USB Endpoint 0 MaxP Register
b7 b5b6 b4 b3 b2 b1 b0
Bit Symbol Bit Name Function R W
WCNT0 to
WCNT4
Reserved
Receive Byte count
Must always be set to "0"
O X
O X
O O O
Symbol
EP0WC
Address
0315
16
When reset
00
16
USB Endpoint 0 OUT Write Count Register
b7 b5b6 b4 b3 b2 b1 b0

Renesas M16C Series Specifications

General

Brand	Renesas
Model	M16C Series
Category	Computer Hardware
Language	English