51 Address bus (AB)-EEWORLD

Collect

The address bus is unidirectional and is used to transmit address information. The width of the address bus is 16 bits, so the external memory can directly address 64K.

The bus width is 16 bits. "Bit" is not bit or byte. The bus width refers to the number of bits of binary data that the bus can transmit simultaneously, or the number of bits of the data bus.

In general, if the address bus is n bits, the addressable space is 2^n bits.

16-bit width: the representable range is 0000-FFFF

Addressing range: 2^16=65536Byte=64KB

When accessing external memory, port P0 is both a true bidirectional data bus port and a time-sharing output 8-bit address port.

The 16-bit address bus is provided by the P0 port through the address latch to provide the lower 8-bit address (A0~A7), and the P2 port directly provides the higher 8-bit address (A8~A15).

(KB, MB, GB are usually represented by K, M, G)

Reference address：51 Address bus (AB)

Previous article：Design of Snake Game Based on Single Chip Microcomputer
Next article：LAN control system - lower computer - single chip microcomputer

Recommended ReadingLatest update time:2024-11-17 06:27

Homemade simple and practical 51 single chip microcomputer development board

1. Circuit Principle The circuit is shown in the figure below. The P0 port of the 89S52 single-chip microcomputer is connected to the data line of the 1602 character LCD screen with an external 8x1kΩ pull-up resistor. P2.5, P2.6, and P2.7 are connected to the three control lines of the 1602 character LCD screen to for

[Microcontroller]

Homemade simple and practical 51 single chip microcomputer development board

[MCU] [Learning Log] 51 MCU Learning Log [Day2, 2022.1.10]

Part 1: Digital Tube 1. Basic knowledge 1. Digital tube pin definition (single digital tube) The upper one is the common cathode connection The bottom one is the common anode connection Divide "8" into 8 segments, namely "A, B, C, D, E, F, G, DP (clockwise)", which just correspond to the 8 bytes of the register.

[Microcontroller]

[MCU] [Learning Log] 51 MCU Learning Log [Day2, 2022.1.10]

Function pointers and reentrant functions in Keil C51

Overview Function pointers are one of the few difficult parts of C. Due to the unique requirements of the 8051 C compiler, function pointers and reentrant functions have more challenges to overcome, mainly due to the passing of function variables. Typically (on most 8051 chips) function variables are passed via stac

[Microcontroller]

Research on the design of external data storage expansion based on MCS-8051 single chip microcomputer

　　0 Introduction 　　With the continuous improvement of the computing speed and processing power of single-chip microcomputers, they are more widely used in various fields. However, with the continuous expansion of its application fields and the continuous improvement of its integration, its internal resources can no

[Microcontroller]

Research on the design of external data storage expansion based on MCS-8051 single chip microcomputer

Source program for controlling alarm using 8051

FLAGBIT 00H ORG 00H START: JB P1.7,START JNB FLAG,NEXT MOV R2, #200 DV: CPL P1.0 LCALL DELY500 LCALL DELY500 DJNZ R2,DV CPL FLAG NEXT: MOV R2,#200 DV1: CPL P1.0 LCALL DELY500 DJNZ R2,DV1 CPL FLAG SJMP START DELY500: MOV R7,#250 LOOP: NOP DJNZ R7,LOOP RIGHT END

[Microcontroller]

Traffic light design with time display based on 51 microcontroller

Function: Traffic light design with time display, 30 seconds north-south green light, east-west red light; 3 flashes of yellow light; switch to 30 seconds east-west green light, north-south red light; The specific timing time can be modified according to the program, with source program and simulation diagram. Simul

[Microcontroller]

Study Notes - 51 MCU Special Function Registers

I. Introduction In the process of learning 51 single-chip microcomputer, we are actually learning how to use its special function registers (some registers are invisible to us). Special function registers are registers corresponding to each functional component in 80C51 single-chip microcomputer, which are used to sto

[Microcontroller]

Study Notes - 51 MCU Special Function Registers

51 UART configuration process

Step 1: Set the input and output properties of TXD and RXD pins according to the definition of each chip Example: P2CR &= 0xFB; //P2^1: UART_TXD, P2^2: UART_RXD Step 2: Set UART working mode Set the SCON register. For example, SH88F02 is set to work mode 1, SCON = 0x40; In the SH88F02 application, it is found

[Microcontroller]

Popular Resources
Popular amplifiers