| Pin | Name | Type | Description |
| 1,23,30,31 | GND | Ground | Digital Ground |
| 2 | TCK | I | Test Clock (TTL Input): Provides the clock to the JTAG test logic. This pin is intemally pulled up to VCC. |
| 3, 5, 29, 32- 34, 37, 38 | NC | | No connection |
| 4 | TRST | I | Test Reset (TTL Input): Asynchronously initializes the JTAG TAP controller by putting it in the Test-Logic-Reset state. This pin is internally pulled down to GND. |
| 6 | REF | I | Reference (TTL): The reference signal, internally pulled down to GND. |
| 7. 28 | V(.C | Power | Power supply SV for PT7A4408J. 3.3V for PT7A4408LJ |
| 8 | OSCo | 0 | Oscillator master clock output (CMOS): Output of 20MHz master clock |
| 9 | OSCi | I | Oscillator master clock input (CMOS): Input of 20MHz master clock (can be connected directly to a clock source) |
| 10 | AGND | Ground | Analog Ground |
| 11 | F16 | 0 | Frame pulse ST-BUS 16.384Mb/s (CMOS): 8kHz frame signal with 61ns low level pulse that marks the beginning of a ST-BUS frame, typically used for ST-BUS opetation at 8.192Mb/s. See figure 10. |
| 12 | RSP | 0 | Receive Sync Pulse (CMOS Output). This is an 8kHz 488ns active high framing pulse, which marks the end of an ST-BUS frame. See Figure 11. |
| 13 | FO | 0 | Frame pulse ST-BUS 2.048 Mb/s (CMOS): 8kHz frame signal with 244ns low level pulse that marks the beginning ofa ST-BUS frame e, typically used for ST-BUS opetation at 2.048Mb/s. See figure 10. |
| 14 | TSP | 0 | Transmit Sync Pulse (CMOS Output). This is an 8kHz 488ns active high framing pulse, which marks the beginning of an ST-BUS frame. See Figure 11. |
| 15 | F8 | 0 | Frame pulse ST-BUS 8.192 Mb/s (CMOS): 8kHz frame signal with 122ns high level pulse that marks the beginning of a ST-BUS frame |
| 16 | C1.5 | 0 | 1.544 MHz clock (CMOS): This output is used in Tl applications. |
| 17 | AVDD | Power | Analog Power Supply: SV for PT7A4408J and 3.3V for PT7A4408LJ |
| 18 | C3 | 0 | 3.088 MHz clock (CMOS): This output is used in Tl applications. |
| 19 | C2 | 0 | 2.048 MHz clock (CMOS): This output is used for ST-BUS operation at 2.048Mb/s. |
| 20 | C4 | 0 | 4.096 MHz clock (CMOS): This output is used for ST-BUS operation at 2.048Mb/s and 4.096Mb/s. |
| 21 | C19 | 0 | Clock 19.44MHz (CMOS Output). This output is used in OC3/STS-3 applications. |
| 22 | ACKi | I | Analog PLL Clock Input (CMOS Input). This input clock is a reference for an internal analog PLL. This pin is internally pulled down to GND. |
| 24 | ACKo | 0 | Analog PLL Clock Output (CMOS Output). This output clock is generated by the internal analog PLL. |
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