| PIN | NAME | TYPE | DESCRIPTION |
| 1 | RESETB | Digital input | NOT reset input (active low, resets digital circuitry) |
| 2 | ID | Digital input | AC link Data slot select. Low = Normal stereo (slots 3,4), High = Surround (slots 7,8), High impedance (Z) = LFE and centre (slots 6,9) |
| 3 | DVDD | Supply | Digital positive supply |
| 4 | XTLIN | Digital input | Clock crystal connection or clock input (XTAL not used) |
| 5 | XTLOUT | Digital output | Clock crystal connection |
| 6 | SDATAOUT | Digital input | Serial data input |
| 7 | BITCLK | Digital output (master) Or digital input (slave) | Serial interface clock output to AC-Iink controller if ID pin held low (WM9709 is master). Serial interface clock input from AC-Iink master if ID pin held either high or high impedance (WM9709 is slave). |
| 8 | DGND | Supply | Digital ground supply |
| 9 | SDATAIN | Digital output | Serial data output to AC-Iink controller |
| 10 | SYNC | Digital input | Serial interface sync pulse from AC-Iink controller |
| 11 | AGND | Supply | Analogue ground supply, chip substrate |
| 12 | NC | | No internal connection |
| 13 | NC | | No internal connection |
| 14 | CAP | Analogue input | Reference input/output; internal divider generates midrail |
| 15 | NC | | No internal connection |
| 16 | LINEOUTL | Analogue output | Main analogue output for left channel |
| 17 | LINEOUTR | Analogue output | Main analogue output for right channel |
| 18 | NC | | No internal connection |
| 19 | AVDD | Supply | Analogue positive supply |
| 20 | AGND | Supply | Analogue ground supply, chip substrate |
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