STAC9752 Datasheet, PDF (84/95 Pages) Integrated Device Technology – TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING

STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
11. TESTABILITY
The STAC9752/9753 has two test modes. One is for ATE in-circuit test and the other is restricted for
manufacturer’s internal use. The STAC9752/9753 enters the ATE in-circuit test mode if
SDATA_OUT is sampled high at the trailing edge of RESET#. Once in the ATE test mode, the digital
AC-Link outputs (BIT_CLK and SDATA_IN) are driven to a high impedance state. This allows ATE
in-circuit testing of the AC'97 controller. Use of the ATE test mode is the recommended means of
removing the CODEC from the AC-Link when another CODEC is to be used as the primary. This
case will never occur during standard operating conditions. Once either of the two test modes have
been entered, the STAC9752/9753 must be issued another RESET# with all AC-Link signals held
low to return to the normal operating mode.
Table 30. Test Mode Activation
SYNC
0
0
1
1
SDATA_OUT
0
1
0
1
Description
Normal AC'97 operation
ATE Test Mode
IDT Internal Test Mode
Reserved
11.0.1.
ATE Test Mode
ATE test mode allows for in-circuit testing to be completed at the board level. For this to work, the
outputs of the device must be driven to a high impedance state (Z). Internal pullups for digital I/O
pins must be disabled in this mode. This mode initiates on the rising edge of RESET# pin. Only a
cold reset will exit the ATE Test Mode.
Table 31. ATE Test Mode Operation
Pin Name
SDATA_OUT
BIT_CLK
SDATA_IN
SYNC
RESET#
N.C.
N.C.
N.C.
GPIO0
GPIO1
CID0
CID1
EAPD
SPDIF
Pin #
5
6
8
10
11
31
33
34
43
44
45
46
47
48
Function
1
Z
Z
0
1
Z
Z
Z
Z
Z
Z
Z
Z
Z
Description
Must be held high at the rising edge of RESET#
Must be held low at rising edge of RESET#
Always an input
Always an input
Always an input
Note: Pins 31, 33, and 34 are NO CONNECTS.
IDT™
84
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206