SH7670 Datasheet, PDF (825/1292 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7670 Series

Section 17 USB 2.0 Host/Function Module (USB)
Buffer memory
64 bytes
PIPEBUF registers
BUFSIZE = 0,
DBLB = 0
64 bytes
64 bytes
BUFSIZE = 0,
DBLB = 1
128 bytes
BUFSIZE = 1,
DBLB = 0
Figure 17.10 Example of Buffer Memory Settings
(f) Buffer Memory Operation (Continuous Transfer Setting)
Either the continuous transfer mode or the non-continuous transfer mode can be selected, using the
CNTMD bit in PIPEnCFG. This selection is valid for PIPE1 to PIPE5.
The continuous transfer mode function is a function that sends and receives multiple transactions
in succession. When the continuous transfer mode is set, data can be transferred without interrupts
being issued to the CPU, up to the buffer sizes assigned for each of the pipes.
In the continuous sending mode, the data being written is divided into packets of the maximum
packet size and sent. If the data being sent is less than the buffer size (short packet, or the integer
multiple of the maximum packet size is less than the buffer size), BVAL = 1 must be set after the
data being sent has been written.
In the continuous reception mode, interrupts are not issued during reception of packets up to the
buffer size, until the transaction counter has ended, or a short packet is received.
Table 17.23 describes the relationship between the transfer mode settings by CNTMD bit and the
timings at which reading data or transmitting data from the FIFO buffer is enabled.
Rev. 1.00 Nov. 14, 2007 Page 799 of 1262
REJ09B0437-0100