STAC9758 Datasheet, PDF (109/119 Pages) Integrated Device Technology – HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS

STAC9758/9759
HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS™
PC AUDIO
11. TESTABILITY
The STAC9758/9759 has three test modes. One is for ATE in-circuit test and the other two are
restricted for internal use. STAC9758/9759 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 dur-
ing standard operating conditions. Once either of the two test modes have been entered, the
STAC9758/9759 must be issued another RESET# with all AC-Link signals held low to return to the
normal operating mode.
Table 26. Test Mode Activation
SYNC
0
0
1
1
SDATA_OUT
0
1
0
1
Description
Normal AC'97 operation
ATE Test Mode
Internal Test Modes
Reserved
11.1. ATE Test Mode
ATE test mode allows for in-circuit testing to be completed at board level. For this to work, the out-
puts of the device must be driven to a high impedance state (Z). Internal pull-ups and pull-downs for
I/O pins are also disabled in this mode. This is the lowest power mode for the device. This mode ini-
tiates on the rising edge of RESET# pin. Only a cold reset will exit the ATE Test Mode.
Table 27. ATE Test Mode Operation
Pin Name
SDATA_OUT
BIT_CLK
SDATA_IN
SYNC
RESET#
GPIO0
GPIO1
GPIO2
GPIO3
CID1
EAPD/SPDIFI
SPDIFO/ADAT
Pin #
5
6
8
10
11
31
33
34
45
46
47
48
Function
1
z
z
0
1
z
z
z
z
z
z
z
Description
Must be held high at the rising edge of RESET#
High impedance state
High impedance state
Must be held low at rising edge of RESET#
High impedance state
High impedance state
High impedance state
High impedance state
High impedance state
High impedance state
High impedance state
High impedance state
IDT™
109
HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS™
STAC9758/9759
V 1.2 1206