CS5376 View Datasheet(PDF) - Cirrus Logic

Part Name

Description

MFG CO.

CS5376

Low Power Multi-Channel Decimation Filter

Cirrus Logic 

CS5376

No delay occurs between receiving the MFLAG

signal from the modulators and being output in the

SD port status word. Depending on the group delay

of the digital filters, the invalid data from the mod-

ulator will not be output for several conversion

words after receiving the MFLAG signal. Also, af-

ter recovery of the modulator and clearing of the

MFLAG signal, some number of conversion words

are required before the digital filter will again out-

put valid data.

See “Modulator Data Interface” on page 49 for

more information about the MFLAG signal from

the modulators.

Channel Number Bits - CH[1:0]

The channel number bits indicate which conversion

channel the data word is from. One CS5376 can fil-

ter data for up to four modulators, the channel num-

ber field encodes which modulator the current data

word is from. Note that the channel number,

CH[1:0], is zero based.

• CH[1:0] = 00 = Channel 1

• CH[1:0] = 01 = Channel 2

• CH[1:0] = 10 = Channel 3

• CH[1:0] = 11 = Channel 4

Time Break Flag - TB

The time break flag marks a timing reference in the

output data stream. When a rising edge is received

on the TIMEB pin a time break event is initiated.

The decimation engine writes the TB flag in the

status byte of the SD port output after a delay pro-

grammed in the TIMEBRK register (0x29). The

TB flag is set in one output word for all enabled

conversion channels. See “Time Break Function”

on page 75 for more information about how the

time break function is used as a timing reference.

Port Overflow Flag - W

The port overflow flag indicates an overflow con-

dition in the SD port data FIFO, and is set by hard-

ware when the decimation engine overwrites a

FIFO register whose data has not been sent. The W

flag is independently set for each output word and

channel.

Conversion Data Word

The last 24 bits of the SD port output word is the

conversion data for the specified channel. The con-

version data is a 24-bit two’s complement value.

See “Digital Decimation Filter” on page 53 for

more information how conversion data is generated

in the digital filters.

DS256PP1

74

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