Epson S2R72V18 Technical Manual page 395

3. Register Details
Bit2 Audio441
Setting this bit to "1" enables the audio class assist function. The audio class assist function is used
when transmitting 16-bit 2-channel PCM data with a sampling frequency of 44.1 kHz via
isochronous transfer at a 1-ms cycle. The size of the data packets transmitted is automatically
adjusted when the audio class assist function is enabled. Nine consecutive transactions with a
176-byte data packet size are followed by one transaction with a 180-byte data packet size.
Bit1-0 TotalSizeFree[1:0]
These set the transfer control using the H_CHx{x=b-e}TotalSize_HH to LL registers.
00: Clears the TranGo bit and ends the transfer once the size set in the
01: Performs the transfer regardless of the H_CHx{x=b-e}TotalSize_HH to LL register
10: A TotalSizeCmp interrupt occurs when the size set in the H_CHx{x=b-e}TotalSize_HH
11: Reserved
378
H_CHx{x=b-e}TotalSize_HH to LL registers has been transferred. A TotalSizeCmp
interrupt then occurs here. For OUT transfers, the final data packet size will be the
smaller of MaxPktSize and TotalSize. For IN transfers, the expected final data packet
size will be the smaller of MaxPktSize and TotalSize.
values. For OUT transfers, the data packet size will be MaxPktSize. For IN transfers,
the expected data packet size will be MaxPktSize. The TranGo bit is not cleared and no
TotalSizeCmp interrupt occurs for this setting, even when the size set in the
H_CHx{x=b-e}TotalSize_HH to LL registers has been transferred.
to LL registers has been transferred. The TranGo bit is not cleared here, but channel
transaction issuing is stopped while the TotalSize value is "0." For OUT transfers, the
data packet size will be the smaller of MaxPktSize and TotalSize. For IN transfers, the
expected data packet size will be the smaller of MaxPktSize and TotalSize.
EPSON
S2R72V18 Technical Manual (Rev.1.00)