SH7205 Datasheet, PDF (1231/1904 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7200 Series

Section 24 USB 2.0 Host/Function Module (USB)
24.3.24 BEMP Interrupt Status Register (BEMPSTS)
BEMPSTS is used to confirm the BEMP interrupt status for each pipe
This register is initialized by a power-on reset.
Bit: 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
—
—
—
—
—
—
PIPE9 PIPE8 PIPE7 PIPE6 PIPE5 PIPE4 PIPE3 PIPE2 PIPE1 PIPE0
BEMP BEMP BEMP BEMP BEMP BEMP BEMP BEMP BEMP BEMP
Initial value: -
-
-
-
-
-
0
0
0
0
0
0
0
0
0
0
R/W: R
R
R
R
R
R R/W* R/W* R/W* R/W* R/W* R/W* R/W* R/W* R/W* R/W*
When this module detects a BEMP interrupt in the pipe for which PID = BUF is set, the
corresponding bit for that pipe is set to 1. This module generates an internal BEMP interrupt
request in the following conditions.
(a) Pipe in the Transmitting Direction
An internal BEMP interrupt request is generated in a transmitting pipe when transmission has
been completed (including zero-length packet transmission) while the FIFO buffer for the pipe is
empty. With a single-buffer configuration, an internal BEMP interrupt request is generated at the
same time as the BEMP interrupt for the pipes other than the DCP.
However, an internal BEMP interrupt request is not generated in the following cases.
• In a double-buffer configuration, writing to the FIFO buffer on the CPU side has been started
when transmission for a single plane of data is completed.
• Buffer is cleared (has become empty) by writing 1 to the ACLRM or BCLR bit.
• When the function module function has been set, IN transfer (zero-length packet transmission)
is executed for the status stage in control transfer.
(b) Pipe in the Receiving Direction
An internal BEMP interrupt request is generated when data of the amount greater than the size set
by MaxPacketSize has been received normally. In this case, this module generates a BEMP
interrupt request, sets the bit corresponding to the pipe to 1, discards the received data, and
modifies the PID bit setting for the pipe to STALL. This module returns no response when the
host controller function is selected, and carries out the STALL response when the function
controller function is selected.
Rev. 1.00 Mar. 25, 2008 Page 1199 of 1868
REJ09B0372-0100