Renesas SH7781 - Manual (Page 1354)

26. Serial Sound Interface (SSI) Module
Rev.1.00 Jan. 10, 2008 Page 1324 of 1658
REJ09B0261-0100
7. Parallel Right Aligned with Delay
As basic sample format configuration except PDTA = 1
System word 1 System word 2
0 0 0 0 0 0 TD3 TD0 TD3 TD2 TD1 TD0 TD3 TD2 TD1 TD0
SSI_SCK
SSI_WS
SSI_SDATA
Figure 26.16 Parallel Right Aligned with Delay
8. Mute Enabled
As basic sample format configuration except MUEN = 1 (TD data ignored)
System word 1 System word 2
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
When MUBN = 1 in transmit mode, a low level is output from the SSI_SDATA pin regardless of padding setting.
SSI_SCK
SSI_WS
SSI_SDATA
Figure 26.17 Mute Enabled
26.4.3 Compressed Modes
The compressed mode is used to transfer a continuous bit stream. This would typically be a
compressed bit stream which requires downstream decoding.
When burst mode is not enabled, there is no concept of a data word. However in order to receive
and transmit it is necessary to transfer between the serial bus and word formatted memory.
Therefore the word boundary selection is arbitrary during receive/transmit and must be dealt with
by another module. When burst mode is enabled then data bits being transmitted can be identified
by virtue of the fact that the serial clock output is only activated when there is a word to be output
and only the required number of clock pulses necessary to clock out each 32-bit word are
generated. The serial bit clock stops at a low level when SSICR.SCKP = 0, and at a high level
when SSICR.SCKP = 1. Note burst mode is only valid in the context of the SSI module being a
transmitter of data. Burst mode data cannot be received by this module.
Data is transmitted and received in blocks of 32 bits, and the first bit received/transmitted bit is bit
31 when stored in memory.