R5S72011 RENESAS [Renesas Technology Corp], R5S72011 Datasheet - Page 806

• Manufacturer Part Number: R5S72011
• Description: 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7200 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

Section 18 Serial Sound Interface (SSI)
Rev. 2.00 Sep. 07, 2007 Page 778 of 1164
REJ09B0321-0200
Bit
31 to 29
28
27
Bit Name
—
DMRQ
UIRQ
Initial
Value
All 0
0
0
R/W
R
R
R/W*
1
Description
Reserved
The read value is not guaranteed. The write value
should always be 0.
DMA Request Status Flag
This status flag allows the CPU to recognize the value
of the DMA request pin on the SSI module.
•
•
Underflow Error Interrupt Status Flag
This status flag indicates that data was supplied at a
lower rate than was required.
In either case, this bit is set to 1 regardless of the value
of the UIEN bit and can be cleared by writing 0 to this
bit.
If UIRQ = 1 and UIEN = 1, an interrupt occurs.
•
•
Note: When underflow error occurs, the current data in
TRMD = 0 (Receive mode)
If DMRQ = 1, the SSIRDR has unread data.
If SSIRDR is read, DMRQ = 0 until there is new
unread data.
TRMD = 1 (Transmit mode)
If DMRQ = 1, SSITDR requires data to be written to
continue the transmission to the audio serial bus.
Once data is written to SSITDR, DMRQ = 0 until it
requires further transmit data.
TRMD = 0 (Receive mode)
If UIRQ = 1, SSIRDR was read before there was
new unread data indicated by the DMRQ or DIRQ
bit. This can lead to the same received sample
being stored twice by the host leading to potential
corruption of multi-channel data.
TRMD = 1 (Transmit mode)
If UIRQ = 1, SSITDR did not have data written to it
before it was required for transmission. This will
lead to the same sample being transmitted once
more and a potential corruption of multi-channel
data. This is more serious error than a receive
mode underflow as the output SSI data results in
error.
the data buffer of this module is transmitted until
the next data is filled.