1. - 2. - 1 2 MCS-51 3 MSC-51 6 4MCS-51 7 5MCS-51/ 9 MCS-51 8 3. - 1 CPU RAM ROM / 4. - 1 1 1976~1978 Intel MCS-48 8 CPU / I/O RAM ROM 1978~1982 I/O 8 16 64K 1982~1990 16 16 CPU 16 RAM ROM Intel MCS-96 12M RAM 232 ROM 8K 8 10 A/D / 1990 ~ 5. - Central Processing Unit CPU CPU / Input/Output I/O 1 2 1.2.1 6. - 1-1 7. - 5 1) 2) CPU 8. - 3) EPROM2764 4) 5) 9. - CPU Central Processing Unit RAM Random Access Memory ROM Read- only Memory / (Input/Output) / 1-2 10. - 1-2 CPU I/O / P0P3 TXD RXD T INT I/O 11. - 1.2.2 12. - 13. - 1.3 MCS-51 MCS-51 MCS-51 1-1 14. - 1-1 MCS-51 ROM ROM RAM I/O ROM EPROM 51 8031 8051 8751 4 KB 128 B 264 KB 216 48 1 5 80C31 80C51 87C51 4 KB 128 B 264 KB 216 48 1 5 52 8032 8052 8752 8 KB 256 B 264 KB 316 48 1 6 80C32 80C52 87C52 8 KB 256 B 264 KB 316 48 1 6 15. - MCS-51 51 52 51 52 52 1- 1 (1) ROM 4 KB 8 KB (2) RAM 128 B 256 B (3) / 2 3 (4) 5 6 1.3.1 51 52 16. - MCS-51 HMOS MOS CHMOS HMOS 1.1 C CHMOS HMOS CHMOS CMOS HMOS HMOS CMOS CHMOS 1.3.2 17. - MCS-51 ROM EPROM ROM , ROM EPROM EPROM Intel EEPROM 1.3.3 ROM 18. - 2 MCS-51 MCS-51 8051 P0 P1 P2 P3 I/O 19. - 2.1 MCS-51 MCS-51 8031 8051 8751 8051 4KB ROM 8751 4KB EPROM 8031 ROM 8051 8051 2-1 2.1.1 8051 20. - 2-1 MCS-51 21. - 1) CPU MCS-51 CPU 8 2) RAM 8051 256 RAM 128 128 128 RAM 22. - 3) ROM 8051 4KB ROM ROM 4) / 8051 16 / 5) I/O MCS-51 4 8 I/O P0 P1 P2 P3 / 23. - 6) MCS-51 7) MCS-51 8051 5 / 8) MCS-51 6 MHz 12 MHz 24. - MCS-51 40 2-2 1) P0.0 P0.7 P0 8 P1.0 P1.7 P1 8 P2.0 P2.7 P2 8 P3.0 P3.7 P3 8 2.1.2 MCS-51 25. - 2-2 MCS-51 P1.01 P1.12 P1.23 P1.34 P1.45 P1.56 P1.67 P1.78 RST/VPD9 RXDP3.010 TXDP3.111 INT0P3.212 INT1P3.313 T0P3.414 T1P3.515 WRP3.616 RDP3.717 XTAL218 XTAL119 VSS20 P2.0 21 P2.1 22 P2.2 23 P2.3 24 P2.4 25 P2.5 26 P2.6 27 P2.7 28 PSEN 29 ALE/PROG 30 EA/VPP 31 P0.7 32 P0.6 33 P0.5 34 P0.4 35 P0.3 36 P0.2 37 P0.1 38 P0.0 39 VCC 40 803180518751 26. - 2 1 P 3 2) 27. - 2.2 8051 2- 3 RAM 2.2.1 128 28. - 2FH 2EH 2DH 2CH 2BH 2AH 29H 28H 27H 26H 25H 24H 23H 22H 21H 20H D7 D6 D5 D4 D3 D2 D1 D0 7FH 7EH 7DH 7CH 7BH 7AH 79H 78H 77H 76H 75H 74H 73H 72H 71H 70H 6FH 6EH 6DH 6CH 6BH 6AH 69H 68H 67H 66H 65H 64H 63H 62H 61H 60H 5FH 5EH 5DH 5CH 5BH 5AH 59H 58H 57H 56H 55H 54H 53H 52H 51H 50H 4FH 4EH 4DH 4CH 4BH 4AH 49H 48H 47H 46H 45H 44H 43H 42H 41H 40H 3FH 3EH 3DH 3CH 3BH 3AH 39H 38H 37H 36H 35H 34H 33H 32H 31H 30H 2FH 2EH 2DH 2CH 2BH 2AH 29H 28H 27H 26H 25H 24H 23H 22H 21H 20H 1FH 1EH 1DH 1CH 1BH 1AH 19H 18H 17H 16H 15H 14H 13H 12H 11H 10H 0FH 0EH 0DH 0CH 0BH 0AH 09H 08H 07H 06H 05H 04H 03H 02H 01H 00H 2 2 RAM 29. - * ACC E0H ACC.7 ACC.0 E7H E0H * B F0H B.7 B.0 F7H F0H * PSW D0H PSW.7 PSW.0 D7H D0H SP 81H DPL 82H ( 8 ) DPH 83H ( 8 ) * IE A8H IE.7 IE.0 AFH A8H * IP B8H IP.7 IP.0 BFH B8H * P0 80H 0 P0.7 P0.0 87H 80H * P1 90H 1 P1.7 P1.0 97H 90H * P2 A0H 2 P2.7 P2.0 A7H A0H * P3 B0H 3 P3.7 P3.0 B7H B0H PCON 87H * SCON 98H SCON.7 SCON.0 9FH 98H SBUF 99H * TCON 88H TCON.7 TCON.0 8FH 88H TMOD 89H TL0 8AH 0 8 TL1 8BH 1 8 TH0 8CH 0 8 TH1 8DH 1 8 2.2.2 128 2 3 MCS-51 30. - P0.n P0.n Q QD T1 T2 VCC MUX / 2 5 P0 2.3.1 P0 2.3 / 31. - 2.3.2 P1 P1.n P1.n Q QD T VCC 2 6 P1 32. - 2.3.3 P2 P2.n P2.n Q QD T VCC MUX 2 7 P2 33. - 2.3.4 P3 P3.n P3.n Q QD T VCC 2 8 P3 34. - 2.4.1 S 1 2 2 4 MCS-51 35. - 1. TTL (a) XTAL1 R XTAL2 VCC XTAL2 XTAL1 VSS (b) 8051 8051 NC XTAL1 XTAL2 VSS (c) 80C51 80 C1 C2 2-9 2-10 36. - 1 ALE S1 S4 S6S5S3S2 () (a) 1 1 S1 S4 S6S5S3S2 (b) 2 1 S1 S4 S6S5S3S2 () (c) 1 2 S1 S4 S6S5S3S2 2 11 MCS-51 / 2 4. MCS-51 3 37. - 1 PC 0000H ACC 00H B 00H PSW 00H SP 07H DPTR 0000H P0 P3 FFH IP XXX00000B IE 0XX00000B TMOD 00H TCON 00H TH0 00H TL0 00H TH1 00H TL1 00H SCON 00H SBUF PCON(CHMOS) 0XXX0000B 2.4.2 38. - 2 D1 D2 RST/VPD VCC VSS RAM 2 12 39. - 3 VCC 8051 VCC RST/VPD VSS R 1k C 22F VCC 8051 VCC RST/VPD VSS R1 1k C1 22F R2 1k C2 22F RESET (a) (b) VCC 8051 VCC RST/VPD VSS R1 200 C 22F R2 1k RESET (c) 2 13 40. - 3 MSC-51 3 1 MCS-51 3.1.1 [ ] [ ] [ ] [ ] 1~6 41. - MCS-51 CPU 42. - 3.1.2 1. 2. 4. 3. 6. 7. 5. 43. - MSC-51 MSC-51 111 l 29 l 24 l 24 l 17 l 17 44. - 4 MCS-51 A B P2 P1 P3 (a) (b) (c) 45. - 4.1 Machine Language 0 1 Assembly Language 46. - High-Level Language PL/M- 51 Franklin C51 MBASIC 51 47. - 4.1.3 4.1 R3 R2 1 4- 1 48. - 4- 1 49. - BINPL MOV A,R2 CPL A ADD A,#01H MOV R2,A R2 MOV A,R3 CPL A ADDC A,#00H MOV R3,A R3 RET 50. - 4.1.4 4.2 X VAR y FUNC y 51. - 4- 2 4- 2 52. - VAR EQU 30H FUNC EQU 31H START MOV A,VAR JZ COMP JNB ACC.7,POSI MOV A,#0FFH SJMP COMP POSI MOV A,#01H COMP MOV FUNC,A 53. - 4- 3 4.1.5 4- 3 54. - 1 2 3 Rn 4 55. - 4.3 1 2 3N N 256 R2 R5 R6 N RAM 23H 23H 24H 4- 4 56. - 4- 4 4.3 57. - ORG 0100H MOV R5,23H ;R5N CLR A ;A MOV R6,#00H ;R6 MOV R4,#01H ;R4 LOOP ADD A,@R4 ; JNC NEXT ;CY=0 256 INC R6 ; NEXT INCR4 ; DJNZ R5,LOOP ; MOV 23H,R6 ; MOV 24H,A ; END 58. - 4.4 10ms 6MHz 6MHz 0.5s DJNZ Rn rel 1s 10ms DELAY MOV R5,#100 DELAY0 MOV R4,#100 DELAY1 DJNZ R4,DELAY1 DJNZ R5,DELAY0 RET 59. - 5 MCS-51 / 5 1 MCS-51 / .1.1 8051 / / TH1 TL1 TH0 TL0 TCON TMOD T1 T0 5 1 8051 / 60. - 5.1.2 / 5 1 M1 M0 0 0 0 13 0 1 1 16 1 0 2 8 1 1 3 0 8 1 TMOD 61. - TCON TCON 8FH 8EH 8DH 8CH 8BH 8AH 89H 88H TF1 TR1 TF0 TR0 IE1 IT1 IE0 IT0 62. - 5.1.3 / 4 1. 0 M1M0 00 / 0 52 12 TL0 (5) TF0 T0 C/ T = 0 C/ T = 1 + INT0 GATE TR0 TH0 (8) 5 2 T0( T1) 0 63. - 2. 1 12 TL0 (8) TF0 T0 C/ T = 0 C/ T = 1 + INT0 GATE TR0 TH0 (8) T0 ( T1 ) 1 64. - 3. 2 12 TL0 (8) TF0 T0 C/ T = 0 C/ T = 1 + INT0 GATE TR0 TH0 (8) 5 3 T 0 ( T1 ) 2 65. - 4. 3 12 TL0 (8) TF0 T0 C/ T = 0 C/ T = 1 + INT0 GATE TR0 TH0 (8) 1/ 12 f osc 1/ 12 f osc TF1 1/ 12 f osc TR1 5 4 T 0 3 T1 66. - / 1 TMOD 2 TL0 TH0 TL1 TH1 3 / 4 / TCON TR1 TR0 1 5. / 67. - 1 M 0 M=213=8192 1 M=216=65536 2 M=28=256 3 M=28=256 X X=M- X M-X *T= X=M- /T T 12 6MHz t=2s 12MHz T=1s 68. - 5.1 12MHz 500s X T=1s 500s +1500 0 X=213- 500*10-6/10-6 =7692=1E0CH 0 TL0 3 0 1E0CH F00CH=1111000001100B F00CH 3 1E0CH F0H TH0 0CH TL0 1 X=216-(500*10-6/10-6)=65536=FE0CH FEH TH1 0CH TL1 69. - 5.2 1 0 1s 0 13 8192*1s=8192s 8ms 125 5ms 200 5000 1 X=M- =8192-5000=3192=C78H=0110001111000B 13 TL1 3 0 TH1 8 X X=0110001100011000B=6318H TH1=63H TL1=18H 0 TMOD=00H 70. - 1s DELAY MOV R0,#200 ; 5ms MOV TMOD,#00H ; 1 0 MOV TH1,#63H ; MOV TL1,#18H SETB TR1 ; T1 LP1 JBC TF1,LP2 ; SJMP LP1 ; 5ms LP2 MOV TH1,#63H ; MOV TL1,#18H DJNZ R0,LP1 ; 1s 71. - 5.3 1 1 1s DELAY MOV R0,#20 ; 50ms MOV TMOD,#10H ; 1 1 MOV TH1,#3CH ; MOV TL1,#0B0H SETB TR1 ; T1 LP1 JBC TF1,LP2 ; SJMP LP1 ; 50ms LP2 MOV TH1,#3CH ; MOV TL1,#0B0H DJNZ R0,LP1 ; 1s RET ; 72. - 5.4 1 2 1s 2 8 256*1s=256s 1s 250s 4000 250 1 X=M- =256-250=6=6H 1 2 TMOD=20H DELAY MOV R7 #40 ; 25ms MOV R6 #100 ; 250s MOV TMOD #20H ; 1 2 MOV TH1 #06H ; MOV TL1 #06H SETB TR1 ; T1 LP1 JBC TF1 LP2 ; SJMP LP1 ; LP2 DJNZ R6 LP1 ; 25ms MOV R6 #100 DJNZ R7 LP1 ; 1s RET ; 73. - 5.2 MCS-51 PC PC SCON IP PX0 1 PT0 1 1 0 PX1 1 0 PS 1 0 0 PT1 0 IE EX0 ET0 EX1 ET1 ES TCON IE0 TF0 IE1 TF1 TI RI RX TX T1 IT1=1 INT1 IT1=0 T0 INT0 IT0=1 IT0=0 EA 5-5 MCS-51 74. - 1 0 0003H T0 000BH 1 0013H T1 001BH 0023H 75. - 2 2 SCON 1 TCON 3 4 5 2 1 3 4 76. - 5.2.4 1. MCS-51 T0 P3.4 T1 P3.5 1 T0 T1 5.5 0 n 0 2 TH0 TFO FFH 0 CPU 77. - MOV TMOD,#06H MOV TH0,#0FFH MOV TL0,#0FFH SETB TR0 SETB ET0 SETB EA T0 P3.4 TL0 1 TF0 1 CPU TH0 TL0 TL0 T0 TF0 1 CPU T0 1 78. - 2. 5- 8 79. - 4 4 OC P3.2 4 EXINT0 EXINT3 0 CPU P1 4 0INT 0INT 80. - ORG 0003H ; 0 AJMP INT0 ; INT0: PUSH PSW ; PUSH ACC JB P1.0,EXT0 ; JB P1.1,EXT1 JB P1.2,EXT2 JB P1.3,EXT3 EXIT: POP ACC ; POP PSW RETI EXT0: ;EXINT0 AJMP EXIT EXT1: ;EXINT1 AJMP EXIT EXT2: ;EXINT2 AJMP EXIT EXT3: ;EXINT3 AJMP EXIT 1 81. - 6 6 1 8051 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23 22 21 P1.0 P1.1 P1.2 P1.3 P1.4 P1.5 P1.6 P1.7 RST RXD/P3.0 TXD/P3.1 INT0/P3.2 INT1/P3.3 T0/P3.4 T1/P3.5 WR/P3.6 RD/P3.7 XTAL2 XTAL1 VSS VCC P0.0/AD0 P0.1/AD1 P0.2/AD2 P0.3/AD3 P0.4/AD4 P0.5/AD5 P0.6/AD6 P0.7/AD7 EA/VPP ALE/PROG PSEN P2.7/A15 P2.6/A14 P2.5/A13 P2.4/A12 P2.3/A11 P2.2/A10 P2.1/A9 P2.0/A8 8031 8051 8751 P1. 7 P1. 6 P1. 5 P1. 4 P1. 3 P1. 2 P1. 1 P1. 0 P3. 7 P3. 6 P3. 5 P3. 4 P3. 3 P3. 2 P3. 1 P3. 0 PSEN EA ALE RESET 8031 8051 8751 P2. 7 P2. 6 P2. 5 P2. 4 P2. 3 P2. 2 P2. 1 P2. 0 P0. 7 P0. 6 P0. 5 P0. 4 P0. 3 P0. 2 P0. 1 P0. 0 ALE A15 A14 A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0 G +5V VCC VSS ( DB) ( AB) ( CB) I / O MCS-51 82. - 6- 1 83. - 6 2 EA 8031 P2.7 P2.0 P0.7 P0.0 PSEN OE A15 A8 CE A7 A0 D7 D0 0K64K 84. - EPROM PSEN P2.0 P2.1 P2.2 P2.3 P2.4 P2.5 P2.6 P2.7 A8 A9 A10 A11 A12 QO A0 A1 A2 A3 A4 A5 A6 A7 Q1 Q2 Q3 Q4 Q5 Q6 Q7 D0 D1 D2 D3 D4 D5 D6 D7 P0.0 P0.1 P0.2 P0.3 P0.4 P0.5 P0.6 P0.7 ALE D0 D1 D2 D3 D4 D5 D6 D7 OEG OE 8031 27C64 CE EA 74HC373 6- 8 85. - E2 PROM 6- 10 E2PROM 86. - P3.7(RD) P2.0 P2.1 P2.2 P2.3 P2.4 P2.5 P2.6 P2.7 A8 A9 A10 QO A7 A6 A5 A4 A3 A2 A1 A0 Q1 Q2 Q3 Q4 Q5 Q6 Q7 D0 D1 D2 D3 D4 D5 D6 D7 P0.0 P0.1 P0.2 P0.3 P0.4 P0.5 P0.6 P0.7 ALE I/O0 I/O1 I/O2 I/O3 I/O4 I/O5 I/O6 I/O7 OEG OE 8031 6116 CE EA P3.6(WR) WE 74HC373 2KB 6 3 87. - 6- 12 1 6264 88. - D7 Q7 Q0 D0 74HC373 A12 A11 A10 A9 A8 CE A7 A0 D7 D0 OE P2.7 P2.6 P2.5 P2.4 P2.3 P2.2 P2.1 P2.0 ALE P0 PSEN WR RD 80C51 IC02764IC02764 D0 OE CEA12 A11 A10 A9 A8 A7 A0 D7 IC02764 D0 OE CEA12 A11 A10 A9 A8 A7 A0 D7 D0 OE CEA12 A11 A10 A9 A8 A7 A0 D7 A8 A9 A10 A11 A12 A8 A9 A10 A11 A12 A8 A9 A10 A11 A12A12 A11 A10 A9 A8 IC12764 D0D0D0D0D7D7D7D7 OEOEOEOE A0A0A0A0 A7A7A7A7 A0A0A0A0 A7A7A7A7 A8A8A8A8 A9A9A9A9 A10A10A10A10 OEOEOEOE CECECECE A11A11A11A11 A12A12A12A12 A10A10A10A10 A0A0A0A0 OEOEOEOE A7A7A7A7 A8A8A8A8 A9A9A9A9 A12A12A12A12 A11A11A11A11 CECECECECECECECE IC26264 IC36264 WE WE D7-D0 D7-D0 G B A Y2 Y1 Y0 74HC139 16KB RAM 16KB EPROM 89. - 7 2 I/O 7.2.1 I/O 7 7- 2 I/O 90. - 7.2.2 8255 I/O 7- 3 8255 1.8255 91. - 7- 4 8255A 92. - 2.MCS-51 8255A 7- 5 8031 8255A 93. - 3.8255 7- 6 8255A 1 94. - 7- 7 C / 2 C / 95. - 7.2.3 RAM I/O 8155 I/O 1.8155 (a) 8155 (b) 8155 7- 12 8155 96. - 7 3 8155 AD0 ~AD7 A7 A6 A5 A4 A3 A2 A1 A0 0 0 0 0 0 1 I/O A 0 1 0 I/O B 0 1 1 C I/O 1 0 0 / 8 1 0 1 / 8 2.8155 RAM I/O 97. - 3.8155 98. - 7- 13 8155 99. - 7- 4 8155 M2 M1 0 0 1 1 0 1 0 1 100. - 7 2 8155 RAM I/O P2.4 P2.3 0 0 RAM E700H E7FFH (256B) 0 1 I/O EF00H / EF01H I/O A EF02H I/O B EF03H C EF04H 8 EF05H 8 AD07 CE RD WR RESET ALE TIME IN TIME OUT PC PB PA IO/ M 81558031 RST RD WR ALE P2.3 P2.4 P0 VCC 7 15 8155 8031 101. - 7 3 MCS-51 7.3.2 1. 7- 17 102. - 7- 18 103. - 7.3.3 1. 7- 19 104. - 2. 7- 20 105. - 7.4.1 LED 7.4 MCS-51 (a) (b) (c) 7- 21 LED I/O 1.LED 106. - 7- 22 8255A 3 LED 3. LED 107. - 4. LED 7- 23 8155 6 LED 108. - 7- 24 109. - 7.4.2 / Intel8279 1.8279 7- 27 8279 110. - 2.8279 7- 28 8279 111. - 5.8279 7- 29 8279 112. - 7- 30 88 113. - 7.5 / A/D 7.5.2 A/D 7- 32 ADC0809 114. - 7- 33 ADC0809 115. - 7- 34 8031 ADC0809 116. - 7.6.2 D/A DAC0832 7.6 / D/A 7- 37 DAC0832 117. - DAC D/A CS Vcc WR1 ILE AGND WR2 DI3 XFER DI2 DI4 DI1 DI5 DI0 DI6 VREF DI7 Rfb IOUT1 DI0 DI7 ILE CS WR1 WR2 ILE1 ILE2 XFER DGND IOUT2 AGND Rfb IOUT2 IOUT1 VREF DAC0832 DAC0832 118. - 3.DAC0832 MCS-51 1 7- 38 119. - 2 7- 40 DAC0832 8031 120. - 8 8 1 8.1.1 1. 8- 2 121. - 2. 8- 3 122. - 8.1.2 8- 4 123. - 8.2 8.2.1 RS-232C 8- 5 PC RS-232 124. - 8- 1 PC RS-232C 9 IO 1 DCD I 2 RXD I 3 TXD O 4 DTR O 5 GNG - 6 DSR I 7 RTS O 8 CTS I 9 RI I 125. - 8- 2 PC RS-232C 25 IO 2 TXD O 3 RXD I 4 RTS O 5 CTS I 6 DSR I 7 GND - 8 DCD I 20 DTR O 22 RI I 126. - 8.2.2 RS-449 RS-422 RS-423 RS-485 RS-232C RS-423 RS-422 RS-485 1 1 1 10 1 10 32 32 15m 1200m (1kb/s) 1200m (90kb/s) 1200m (100kb/s) 20kb/s 100kb/s (12m) 10Mb/s (12m) 10Mb/s (15m) ( ) 25V 6V 6V -7V +12V ( ) 5V( ) 15V( ) 3.6V( ) 6V( ) 2V( ) 6V( ) 1.5V( ) 5V( ) 3k 7k 450 100 54 ( ) Vmax/300 ( ) 100A( ) 100A( ) 100A( ) 15V 10V 12V -7V +12V 3V 200mV 200mV 200mV 2k 7k 4kmi n 4kmin 12kmin 127. - 8.3 MCS-51 8.3.1 MCS-51 8- 11 MCS-51 128. - 1. SCON 8- 12 SCON 8- 3 SM0 SM1 0 0 0 fosc /12 0 1 1 8 UART T1 /n 1 0 2 9 UART fosc /64 fosc /32 1 1 3 9 UART T1 /n 129. - 2. PCON 8- 13 PCON 130. - 1 0 0 8.3.2 MCS-51 MCS-51 SCON SM1 SM0 131. - 2 1 1 8 1 132. - 3 2 2 9 133. - 8.3.3 MCS-51 1. 0 2 0 2 0 1/12 fosc /12 2 PCON SMOD SMOD=0 fosc /64 SMOD=1 fosc /32 2. 1 3 1 3 SMOD T1 =2SMOD/32 T1 134. - ( 1 3) fosc =6M fosc =12M fosc = 11.059M SMOD T1 SMO D T1 SMO D T1 62.5k 1 2 FFH 19.2k 1 2 FDH 9.6k 0 2 FDH 4.8k 1 2 F3H 0 2 FAH 2.4k 1 2 F3H 1 2 F3H 0 2 F4H 1.2k 1 2 E6H 0 2 E6H 0 2 E8H 600 1 2 CCH 0 2 CCH 0 2 D0H 300 0 2 CCH 0 2 98H 0 2 A0H 137.5 1 2 1DH 0 2 1DH 0 2 2EH 110 0 2 72H 0 1 FEEBH 0 1 FEFFH 8- 4 135. - 8.4 MCS-51 8.4.1 8- 20 136. - 8.4.3 8- 21 137. - 8.5 PC 8.5.1 8- 22 PC