| 40L PDIP Pin# | 44L QFP Pin# | 44L PLCC Pin# | Symbol | Active | lO | Names |
| 1 | 40 | 2 | P1.O/T2 | | i/o | bit o of port l & timer 2 clock out |
| 2 | 41 | 3 | P1.1/T2EX | | i/o | bit l of port l & timer 2 control |
| 3 | 42 | 4 | P1.2 | | i/o | bit 2 0f port 1 |
| 4 | 43 | 5 | P1.3/SPWMO | | i/o | bit 3 0f port l & SPWM channel 0 |
| 5 | 44 | 6 | P1.4/SPWM1 | | i/o | bit 4 0f port l & SPWM channel 1 |
| 6 | 1 | 7 | P1.5/SPWM2 | | i/o | bit 5 0f port l & SPWM channel 2 |
| 7 | 2 | 8 | P1.6/SPWM3 | | i/o | bit 6 0f port l & SPWM channel 3 |
| 8 | 3 | 9 | P1.7/SPWM4 | | i/o | bit 7 0f port l & SPWM channel 4, |
| 9 | 4 | 10 | RES | H | l | Reset |
| 10 | 5 | 11 | P3.O/RXD | | i/o | bit o of port 3 & Receive data |
| 11 | 7 | 13 | P3.1/TXD | | i/o | bit l of port 3 & Transmit data |
| 12 | 8 | 14 | P3.2/#INTO | Ll - | i/o | bit 2 0f port 3 & low true interrupt 0 |
| 13 | 9 | 15 | P3.3/#INT1 | Ll - | i/o | bit 3 0f port 3 & low true interrupt 1 |
| 14 | 10 | 16 | P3.4/TO | | i/o | bit 4 0f port 3 & Timer 0 & |
| 15 | 11 | 17 | P3.5/T1 | | i/o | bit 5 0f port 3 & Timer 1 |
| 16 | 12 | 18 | P3.6/#WR | | i/o | bit 6 0f port 3 & ext. memory write |
| 17 | 13 | 19 | P3.7/#RD | | i/o | bit 7 0f port 3 & ext. mem. read |
| 18 | 14 | 20 | XTAL2 | | O | Crystal out |
| 19 | 15 | 21 | XTAL1 | | l | Crystal in |
| 20 | 16 | 22 | VSS | | | Sink Voltage, Ground |
| 21 | 18 | 24 | P2.O/A8 | | i/o | bit o of port 2 & bit 8 0f ext. memory address |
| 22 | 19 | 25 | P2.1/A9 | | i/o | bit l of port 2 & bit 9 0f ext. memory address |
| 23 | 20 | 26 | P2.2/A10 | | i/o | bit 2 0f port 2 & bit 10 0f ext. memory address |
| 24 | 21 | 27 | P2.3/A11 | | i/o | bit 3 0f port 2 & bit 11 0f ext. memory address |
| 25 | 22 | 28 | P2.4/A12 | | i/o | bit 4 0f port 2 & bit 12 0f ext. memory address |
| 26 | 23 | 29 | P2.5/A13 | | i/o | bit 5 0f port 2 & bit 13 0f ext. memory address |
| 27 | 24 | 30 | P2.6/A14 | | i/o | bit 6 0f port 2 & bit 14 0f ext. memory address |
| 28 | 25 | 31 | P2.7/A15 | | i/o | bit 7 0f port 2 & bit 15 0f ext. memory address |
| 29 | 26 | 32 | #PSEN | | 0 | program storage enable |
| 30 | 27 | 33 | ALE | | 0 | address latch enable |
| 31 | 29 | 35 | #EA | L | l | external access |
| 32 | 30 | 36 | P0.7/AD7 | | i/o | bit 7 0f port 0 & data/address bit 7 0f ext. memory |
| 33 | 31 | 37 | P0.6/AD6 | | i/o | bit 6 0f port 0 & data/address bit 6 0f ext. memory |
| 34 | 32 | 38 | P0.5/AD5 | | i/o | bit 5 0f port 0 & data/address bit 5 0f ext. memory |
| 35 | 33 | 39 | P0.4/AD4 | | i/o | bit 4 0f port 0 & data/address bit 4 0f ext. memory |
| 36 | 34 | 40 | P0.3/AD3 | | i/o | bit 3 0f port 0 & data/address bit 3 0f ext. memory |
| 37 | 35 | 41 | P0.2/AD2 | | i/o | bit 2 0f port 0 & data/address bit 2 0f ext. memory |
| 38 | 36 | 42 | PO.1/AD1 | | i/o | bit l of port 0 & data/address bit l of ext. memory |
| 39 | 37 | 43 | PO.O/ADO | | i/o | bit o of port 0 & data/address bit o of ext. memory |
| 40 | 38 | 44 | VDD | | | Drive Voltage, +5 Vcc |
| | 17 | 23 | P4.0 | | i/o | bit o of Port4 |
| | 28 | 34 | P4.1 | | i/o | bitl of Port4 |
| | 39 | 1 | P4.2 | | i/o | bit 2 0f Port4 |
| | 6 | 12 | P4.3 | | i/o | bit 3 0f Port4 |
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