Cirrus Logic CS4341A - Manual (Page 7)

CS4341A
DS582F2 7
3. APPLICATIONS
3.1 Upgrading from the CS4341 to the CS4341A
The CS4341A is pin and functionally compatible with all CS4341 designs, operating at the standard audio
sample rates, that use pin 3 as a serial clock input. In addition to the features of the CS4341, the CS4341A
supports standard sample rates up to 192 kHz, as well as automatic mode detection for sample rates be-
tween 4 and 200 kHz. The automatic speed mode detection feature allows sample rate changes between
single, double and quad-speed modes without external intervention.
The CS4341A does not support an internal serial clock mode, sample rates between 50 kHz and 84 kHz
(unless otherwise stated), or 2.7 V operation as does the CS4341.
3.2 Sample Rate Range/Operational Mode Detect
The device operates in one of three operational modes. The allowed sample rate range in each mode will
depend on whether the Auto-Detect Defeat bit is enabled/disabled.
3.2.1 Auto-Detect Enabled
The Auto-Detect feature is enabled by default in the control port register 5.1. In this state, the
CS4341A will auto-detect the correct mode when the input sample rate (F
s
), defined by the LRCK
frequency, falls within one of the ranges illustrated in Table 1. Sample rates outside the specified
range for each mode are not supported.
3.2.2 Auto-Detect Disabled
The Auto-Detect feature can be defeated via the control port register 5.1. In this state, the CS4341A
will not auto-detect the correct mode based on the input sample rate (F
s
). The operational mode
must be set appropriately if F
s
falls within one of the ranges illustrated in Table 2. Please refer to
section 5.1.1 for implementation details. Sample rates outside the specified range for each mode
are not supported.
Input Sample Rate (F
S
) MODE
4 kHz - 50 kHz Single Speed Mode
84 kHz - 100 kHz Double Speed Mode
170 kHz - 200 kHz Quad Speed Mode
Table 1. CS4341A Auto-Detect
MC1 MC0 Input Sample Rate (F
S
) MODE
0 0 4 kHz - 50 kHz Single Speed Mode
0 1 50 kHz - 100 kHz Double Speed Mode
1 0 100 kHz - 200 kHz Quad Speed Mode
Table 2. CS4341A Mode Select