CS8406-CSZ datasheet(38/39 Pages) CIRRUS

38 / 39 page

DS580F6

CS8406

16.1.3.2 Two-Byte Mode

There are those applications in which the A and B channel status blocks will not be the same, and the user

is interested in accessing both blocks. In these situations, Two-Byte Mode should be used to access the E

buffer.

In this mode, a read will cause the CS8406 to output two bytes from its control port. The first byte out will

represent the A channel status data, and the 2nd byte will represent the B channel status data. Writing is

similar, in that two bytes must now be input to the CS8406's control port. The A channel status data is first;

B channel status data second.

16.2 AES3 User (U) Bit Management

The CS8406 U bit manager has two operating modes:

Mode 1. Transmit all zeros.

Mode 2. Block mode.

16.2.1

Mode 1: Transmit All Zeros

Mode 1 causes only zeros to be transmitted in the output U data, regardless of E buffer contents. This

mode is intended for the user who wants the output U channel to contain no data.

16.2.2

Mode 2: Block Mode

Mode 2 is very similar to the scheme used to control the C bits. Entire blocks of U data are buffered using

2 block-sized RAMs to perform the buffering. The user has access to the first buffer, denoted the E buffer,

through the control port. It is the only mode in which the user can merge his own U data into the transmit-

ted AES3 data stream. The U buffer access only operates in Two-Byte Mode, since there is no concept

of A and B blocks for user data. The ar rangement of the data is as followings: Bit15[A7] Bit14[B7]

Bit13[A6] Bit12 [B6]...Bit1 [A0] Bit0[B0]. The arrangement of the data in the each byte is that the MSB is

the first transmitted bit. The bit for the A subframe is followed by the bit for the B subframe.

CS8406-CSZ Fiches technique(PDF) 38 Page - Cirrus Logic