TLC320AD91 Datasheet, PDF (40/43 Pages) Texas Instruments – Stereo Audio Codec

5.2 The Texas Instruments TLC320AD91C Connected to an AC‘97 Compliant
Digital Controller
The TLC320AD91C communicates with an AC‘97 compliant digital controller through the digital serial link
or AC-link. In addition to all digital audio streams, command and status information is also communicated
over this point-to-point serial connection. This connection is shown in Figure 5–2.
SYNC
AC’97 Compliant
Digital Controller
BITCLK
SDOUT
SDATIN
TLC320AD91C
RESET
Figure 5–2. Connection to an AC‘97 Digital Controller
5.3 Testability
5.3.1 Activating the Test Modes
The TLC320AD91C has two test modes. One mode is for ATE in circuit test and the other mode is for Texas
Instruments specific tests. The two test modes are activated according to the following:
• The TLC320AD91C enters the ATE in circuit test mode if SDATA_OUT is sampled high at the
trailing edge of RESET.
• The TLC320AD91C enters the Texas Instruments test mode when coming out of reset if SYNC
is high.
• The TLC320AD91C enters Texas Instruments Scan Test mode when coming out of RESET when
both SYNC and SDOUT are held high.
These cases should never occur during standard operating conditions.
Regardless of the test mode, the digital controller must issue a cold reset to resume normal operation of the
TLC320AD91C.
5.3.2 Test Mode Functions – ATE in Circuit Test Mode
When the TLC320AD91C is placed in the ATE test mode, the TLC32AD91C digital AC-Link outputs (i.e.,
BITCLK and SDATIN) are driven to a high-impedance state. This condition allows ATE in circuit testing of
the digital controller.
5–2