CS5376A Datasheet, PDF (28/107 Pages) Cirrus Logic – LOW POWER MULTI CHANNEL DECIMATION FILTER

CS5376A
0000h
0010h
Mfg Header
8-bit Command
N x 24-bit Data
8-bit Command
N x 24-bit Data
...
1FFFh
EEPROM
Manufacturing
Information
EEPROM
Command and
Data Values
Figure 16. 8 Kbyte EEPROM Memory Organization
5 KByte (40 Kbit), which includes command over-
head:
Memory Requirement
Digital Filter Registers (22)
FIR Coefficients (255+255)
IIR Coefficients (3+5)
Test Bit Stream Data (1024)
‘Filter Start’ Command
Total Bytes
Bytes
154
1537
25
3076
1
4793
Table 4. Maximum EEPROM Configuration
Supported serial configuration EEPROMs are
SPI mode 0 (0,0) compatible, 16-bit addresses, 8-
bit data, larger than 5 KByte (40 KBit). ATMEL
AT25640, AT25128, or similar serial EEPROMs
are recommended.
8.4 EEPROM Configuration Commands
A summary of available EEPROM commands is
shown in Table 5.
Write DF Register - 0x01
This EEPROM command writes a data value to the
specified digital filter register. Digital filter regis-
ters control hardware peripherals and filtering
functions. See “Digital Filter Registers” on page 87
for the bit definitions of the digital filter registers.
Sample Command:
Write digital filter register 0x00 with data value
0x070431. Then write 0x20 with data 0x000240.
01 00 00 00 07 04 31
01 00 00 20 00 02 40
Write FIR Coefficients - 0x02
This EEPROM command writes custom coeffi-
cients for the FIR1 and FIR2 filters. The first two
data words set the number of FIR1 and FIR2 coef-
ficients to be written. The remaining data words are
the concatenated FIR1 and FIR2 coefficients.
A maximum of 255 coefficients can be written for
each FIR filter, though the available digital filter
computation cycles will limit their practical size.
See “FIR Filter” on page 47 for more information
about FIR filter coefficients.
Sample Command:
Write FIR1 coefficients 0x00022E, 0x000771 then
FIR2 coefficients 0xFFFFB9, 0xFFFE8D.
02 00 00 02 00 00 02
00 02 2E 00 07 71 FF FF B9 FF FE 8D
Write IIR Coefficients - 0x03
This EEPROM command writes custom coeffi-
cients for the two stage IIR filter. The IIR architec-
ture and number of coefficients is fixed, so eight
data words containing coefficient values always
immediately follow the command byte. The IIR co-
efficient write order is: a11, b10, b11, a21, a22,
b20, b21, and b22. See “IIR Filter” on page 55 for
more information about IIR filter coefficients.
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