Cirrus Logic CS5376A - Manual (Page 78)

CS5376A
DS612F4 78
22.DEVICE REVISION HISTORY
The CS5376A is a pin compatible upgrade to the
CS5376. The part family has had three revisions:
CS5376 rev A
CS5376 rev B
CS5376A rev A
The part number change for CS5376A reflects ad-
ditional functionality built into the device.
22.1 Changes from CS5376 rev A to
CS5376 rev B
New Sinc Filter, SINC3
Added a new sinc filter, SINC3, between the previ-
ous sinc filters and FIR1. Will permit higher deci-
mation rates for seismology applications. Not used
for 0.25 ms, 0.5 ms, 1 ms, or 2 ms output rates to
maintain backward compatibility.
Added FIR1 Coefficients
Included an improved FIR1 filter to compensate for
sinc filter droop. Previous filter had stop band fre-
quency components up to -100 dB not removed by
the FIR2 brick wall filter. Required stop band at-
tenuation is 130 dB minimum. Previous FIR1 filter
coefficients still included to maintain backwards
compatibility.
Added IIR Coefficients
Included 3 Hz IIR1 and IIR2 filter coefficients for
the 0.5 ms, 1 ms, 2 ms, 3 ms, and 4 ms configura-
tions (5 sets IIR1, 5 sets IIR2). Previous
2 Hz @ 1 ms coefficient set was removed.
Modified Output Word Rate Selection
Changed the DEC bit settings in the FILTCFG reg-
ister used to select an output word rate. Re-num-
bered to include the new 120 Hz, 60 Hz, 30 Hz,
15 Hz, and 7.5 Hz output rates. Other settings the
same for backward compatibility.
Modified ROM Coefficient Selection Meth-
od
Changed the ROM coefficient selection routines
(SPI and EEPROM) to require a 24 bit data word.
Previously no data word was required, only the
command byte. The data word is parsed to select
the FIR1, FIR2, IIR1, and IIR2 coefficient sets.
Modified ROM TBS Data Selection Method
Changed the ROM test bit stream selection routine
(SPI and EEPROM) to require a 24 bit data word.
Previously no data word was required, only the
command byte. The data word scales the ROM test
bit stream data to a user selected amplitude.
Modified SPI port to strobe SINT pin
The SPI port now pulses the SINT pin whenever
data is received. Can be used by a microcontroller
to trigger additional data writes. Eliminates the
need to poll the e2dreq bit.
Fixed continuous synchronization opera-
tion
The synchronization operation was modified to
permit continuous re-sync. The SD port FIFO is no
longer reset by the SYNC interrupt.
Corrected EEPROM loader bug
The EEPROM loader bug is fixed. A preamble to
write required constants into memory is no longer
required.
22.2 Changes from CS5376 rev B to
CS5376A rev A
Fixed synchronization repeatability bug
Identical synchronization signals previously
caused different impulse responses from multi-
ple devices. Synchronization is now repeatable.