ST75951 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'ST75951' PDF : 21 Pages View PDF
ST75951
FUNCTIONAL DESCRIPTION (continued)
Figure 4
REG3 BIT4 = 1
PWRDWN
Ring
Output Pin
Normal
GPI '1'
SSI
ON
Wake-up on Ring
Ring
OFF
Off-Hook
ON
Figure 5
REG3 BIT4 = 1
PWRDWN
Ring or
non-masked GPIO
Normal
GPI
Wake-up on Interrupt
Ring
Ring
Off-Hook
SSI
ON
OFF
Processor reads REG2
ST75951 resets Bit GPI
ON
OFF
ON OFF ON
5 - Mode of Operation
Thanks to MCM and M/S programmation pins we
can get the following configuration.
Configuration 1 : MCM = M/S = ’1’.
ST75951 is in master mode and we have :
FS = FQ / (M x Q x OVER). FS is an output.
(see Figure 6).
Configuration 2 : MCM = ’1’, M/S = ’ 0 ’.
ST75951 is in slave mode and the processor pro-
vides FS = (R x SCLK) OVER. FS is an input
(see Figure 7).
Configuration 3 : MCM = ’0’, M/S = ’1’.
ST75951 is in master mode and we have :
FS = FQ / (OVER). FS is an output (see Figure 8).
Configuration 4 : MCM = ’0’, M/S = ’ 0 ’.
The configuration 4 is equivalent to configuration 3
but the processor generates the FS and control the
phase.
ST75951 is in slave mode and the processor pro-
vides FS = (R x SCLK)/OVER. FS is an input
(see Figure 9).
Configuration 5 : Master codec 1 : MCM = ’0’,
M/S = ’ 1 ’. Slave codec 2 : MCM = ’0’, M/S = ’ 0 ’.
This is a dual codec application running on the
same SSI. The master codec has his data in times-
lot 0 ( bit 0 to bit15 ) and the slave codec has his
data in timeslot 1 (bit 16 to bit 31) thanks to the
programmation of TS (see Figure 10).
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