80C51
8051 MCS-51 Intel [ 2 ]. 8051 (. 2.1), . , : P PDIP-40, D CerDIP-40, N PLCC-44, S PQFP-44.
. 2.1. 8051 MCS-51 Intel
8051 ( 8051) MCS-51. , . (CHMOS Complementary High-performance Metal-Oxide-Semiconductor) ( )
(. 2.2). .
. 2.2. 8051 ( DIP-40)
2.2.1. (computing architecture) , , , , [ 3 ].
2.2.2. 80C51 [ 5 ]:
1) 8- , ,
2) ,
3) 64 ,
4) 64 ,
5) 4 ,
6) 128 ,
7) 32 /
8) 16- /,
9) ,
10) (6 /5 ),
11) .
2.2.3. 8051 . 2.3, CPU , OSC , XTAL1, XTAL2 , BUS CONTROLLER , PSEN , ALE , EA CPU , RST , I/O PORTS /, P0, P1, P2, P3 /, SERIAL PORT , T/ 0, T/C 1 /, 128 BYTES RAM 128 , 4K ROM 4 , IC , INTERRUPTS .
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. 2.3. 8051
. ().
2.3.1. CPU . .
2.3.2. 80C51 : (program memory) 64 , (external data memory) 64 , (internal data memory) 128 (SFR Special Function Register) 128 (. 2.4).
8051BHP , 4 .
2.3.3. . , (ROM Read Only Memory). 80C51 (.
. 2.1): (8031BH), (80C51BH), , (80C51BHP), , (D87C51), (P87C51). P87C51 D87C51 , , , D87C51 , .
, CPU , EA=0 (External Access).
PSEN (Program Storage Enable).
EA=1. CPU PSEN .
. 2.4. 80C51
2.3.4. (data memory) . , , (RAM Random Access Memory). RD (read) WR (write).
2.3.5. . RD PSEN , /.
2.4.1. ( RST) CPU 0000H. , EA=1 (. . 2.4), ( 4 ) , . ( ), EA 0.
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2.4.2. , 0003, (8 ). (0003, 000BH, 0013H, 001BH, 0023), , (. 2.17).
2.4.3. . 2.5, A0 ¸ A7 , A8 ¸ A15 , OE CS , DATA , , LATCH - (8- , ).
P0 , . P2 .
(time-division multiplexing) / .
/ P0 ALE PSEN, . ALE (Address Latch Enable), -, , .. - , P0 ALE. PSEN . CS (Chip Select) CS=0, PSEN=0 OE (Output Enable) , (DATA) P0 .
. 2.5. EPROM 80C51
2.9.
2.4.4.
16- ( , , 64 ), , , .
2.5.1. 8051 ( 8051BHP) 64
( 8051BHP 4 ). 32 . 2.6.
, , P0 . / . P2 . WR RD, , , 3.6 P3.7 (. . 2.2). 2.9.
. 2.6. 32K RAM 8051
2.5.2. , 64 , 2 , 64 , , 32 / (- , ..). 0 CS. , CS 2.7, . 2.6, , 0000 ¸ 7FFFH, 8000 ¸ FFFFH .
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2.5.3. 8051 128 (. 2.7). (. 2.8).
. 2.7.
, 00 1F, . 4 8 . R0 ¸ R7. . () (. 2.8.). ( ) (. 2.6).
, 20 2F (.2.1). MCS-51 (. 2.7).
2.1