SH7670 Datasheet, PDF (622/1292 Pages) Renesas Technology Corp – 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7670 Series

Section 16 Serial Sound Interface (SSI)
Initial
Bit
Bit Name Value R/W Description
27
UIRQ
0
R/W* 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.
• 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.
Note: When underflow error occurs, the current data in
the data buffer of this module is transmitted until
the next data is filled.
Rev. 1.00 Nov. 14, 2007 Page 596 of 1262
REJ09B0437-0100