Atmel C51 Manual

Atmel 8051 Microcontrollers Hardware Manual

The 8051 Instruction Set1-6 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Note that Boolean operations can be performed on any byte in th

The 8051 Instruction SetAtmel 8051 Microcontrollers Hardware Manual 1-74316A–8051–01/04This means the stack can go into the Upper 128, if they are imp

The 8051 Instruction Set1-8 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04To right-shift by an odd number of digits, a one-digit shift mu

The 8051 Instruction SetAtmel 8051 Microcontrollers Hardware Manual 1-94316A–8051–01/04repeated for location 2DH. The CJNE instruction (Compare and Ju

The 8051 Instruction Set1-10 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04MOV A, ENTRY_NUMBERCALLTABLEThe subroutine “TABLE” would look

The 8051 Instruction SetAtmel 8051 Microcontrollers Hardware Manual 1-114316A–8051–01/04In this example, FLAG is the name of any addressable bit in th

The 8051 Instruction Set1-12 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04The SJMP instruction encodes the destination address as relati

The 8051 Instruction SetAtmel 8051 Microcontrollers Hardware Manual 1-134316A–8051–01/04done. If there is no interrupt in progress at the time RETI is

The 8051 Instruction Set1-14 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Table 1-12. 8051 Instruction TablexFINC R71-1DEC R71-1ADD A,R

The 8051 Instruction SetAtmel 8051 Microcontrollers Hardware Manual 1-154316A–8051–01/04x7INC @R11-1DEC @R11-1ADD A,@R11-1,C,OV,ACADDC A,@R11-1,C,OV,A

Atmel 8051 Microcontrollers Hardware Manual 14316A–8051–01/04Section 1The C51 Instruction Set...

Atmel 8051 Microcontrollers Hardware Manual 1-16Rev. 4316A–8051–01/04

Atmel 8051 Microcontrollers Hardware Manual 2-17Rev. 4316A–8051–01/04Section 2Common Features Description2.1 Introduction This chapter presents a com

Common Features Description2-18 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Figure 2-1. 8051 Architecture Block DiagramNote: (*)For Ti

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-194316A–8051–01/04Note: Reserved User software should not write to the reser

Common Features Description2-20 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Table 2-2. PSW: Program Status Word Register2.2.4 Stack Po

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-214316A–8051–01/042.2.10 Control Registers Special Function Registers IP, IE

Common Features Description2-22 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/042.4 CPU Timing2.4.1 X1 Mode (Standard Mode)A machine cycle

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-234316A–8051–01/04Figure 2-3. 80C51 fetch/Execute Sequences.2.4.2 X2 Mode Th

Common Features Description2-24 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/042.5 Port Structures and OperationAll four ports in the 80C5

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-254316A–8051–01/04Figure 2-4. 80C51 Port Bit Latches and I/O Buffers.As show

Table of Contents2 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/042.5 Port Structures and Operation ...

Common Features Description2-26 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04in the data sheets) when externally pulled low. Port 0, on

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-274316A–8051–01/04up P2 to drive the transistor. Figure 2-6 shows an example

Common Features Description2-28 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04CLR PX.Y(clear bit Y of Port X)SETB PX.Y(set bit Y of Port

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-294316A–8051–01/04When the CPU is executing out of external Program Memory, a

Common Features Description2-30 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04that purpose ALE is activated twice every machine cycle. Th

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-314316A–8051–01/042.9 Timer/Counters The Atmel 80C51 Microcontrollers impleme

Common Features Description2-32 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04For normal timer operation (GATE0= 0), setting TR0 allows T

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-334316A–8051–01/04Figure 2-10. Timer/Counter x (x = 0 or 1) in Mode 12.10.3

Common Features Description2-34 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Figure 2-12. Timer/Counter 0 in Mode 3: Two 8-bit Counters

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-354316A–8051–01/04Figure 2-13. Timer/Counter 1 Mode 0: 13-bit Counter 2.11.2

Table of ContentsAtmel 8051 Microcontrollers Hardware Manual 34316A–8051–01/042.15.1 Multiprocessor Communications ...

Common Features Description2-36 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Figure 2-15. Timer Interrupt System2.11.6 Timer Registers

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-374316A–8051–01/04Reset Value = 0000 0000bTable 2-6. TH0 Register - TH0 (S:8

Common Features Description2-38 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Table 2-7. TL0 Register - TL0 (S:8Ah)Timer 0 Low Byte Regi

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-394316A–8051–01/042.12 Timer 2 Timer 2 is a 16-bit timer/counter which is pre

Common Features Description2-40 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04but with the added feature that a 1-to-0 transition at exte

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-414316A–8051–01/04depending on the system oscillator frequency and the value

Common Features Description2-42 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Reset Value = 0000 0000bBit addressableBit NumberBit Mnemon

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-434316A–8051–01/04Table 2-12. T2MOD Register - T2MOD (S:C9h)Timer 2 Mode Con

Common Features Description2-44 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Table 2-14. TL2 Register - TL2 (S:CCh) Timer 2 Low Byte Re

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-454316A–8051–01/04The serial port can operate in 4 modes:Mode 0: Serial data

Atmel 8051 Microcontrollers Hardware Manual 1-1Rev. 4316A–8051–01/04Section 1The 8051 Instruction SetThe 8051 instruction set is optimized for 8-bit c

Common Features Description2-46 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Reset Value = 0000 0000bBit addressable2.13.1 Baud Rates Th

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-474316A–8051–01/04The baud rate in Mode 2 depends on the value of bit SMOD in

Common Features Description2-48 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Figure 2-20. Internal Baud Rate• The baud rate for UART is

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-494316A–8051–01/042.13.4 Using Timer 1 to Generate Baud RatesWhen Timer 1 is

Common Features Description2-50 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Figure 2-22. Timer 2 in Baud Rate Generator Mode.The baud

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-514316A–8051–01/04Figure 2-23. Timer 2 Generated Commonly Used Baud RatesXX-

Common Features Description2-52 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04As data bits come in from the right, 1’s shift out to the l

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-534316A–8051–01/04Figure 2-24. Serial Port Mode 0

Common Features Description2-54 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/042.14 Framing Error DetectionFraming bit error detection is

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-554316A–8051–01/042.15 Automatic Address Recognition2.15.1 Multiprocessor Com

The 8051 Instruction Set1-2 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Table 1-1. PSW: Program Status Word Register1.2 Addressing Mod

Common Features Description2-56 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Slave C:SADDR1111 0011bSADEN1111 1101bGiven1111 00X1bThe SA

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-574316A–8051–01/04Table 2-21. SADDR RegisterSADDR - Slave Address Register (

Common Features Description2-58 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04UART RegistersReset Value = 0000 0000bBit addressableTable

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-594316A–8051–01/04Table 2-23. SADEN RegisterSADEN - Slave Address Mask Regis

Common Features Description2-60 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Reset Value = 0000 0000bBit addressableTable 2-27. T2CON R

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-614316A–8051–01/04Reset Value = 00X1 0000bNot bit addressablePower-off flag r

Common Features Description2-62 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04Reset Value = XXX0 0000bNot bit addressable2.16 Interrupts

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-634316A–8051–01/042.16.1 How Interrupts Are HandledThe interrupt flags are sa

Common Features Description2-64 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/04The hardware-generated LCALL pushes the contents of the Pro

Common Features DescriptionAtmel 8051 Microcontrollers Hardware Manual 2-654316A–8051–01/04complete the instruction in progress, plus 4 cycles to comp

The 8051 Instruction SetAtmel 8051 Microcontrollers Hardware Manual 1-34316A–8051–01/04to point to it. The opcode does this itself. Instructions that

Printed on recycled paper.Disclaimer: Atmel Corporation makes no warranty for the use of its products, other than those expressly contained in the Co

The 8051 Instruction Set1-4 Atmel 8051 Microcontrollers Hardware Manual4316A–8051–01/041.3 Arithmetic InstructionsThe menu of arithmetic instructions

The 8051 Instruction SetAtmel 8051 Microcontrollers Hardware Manual 1-54316A–8051–01/04The DA A instruction is for BCD arithmetic operations. In BCD a