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What is Difference between internal ram and external ram in 8051?
Wiki User
∙ 12y ago
Internal Ram in 8051
the 8051 includes a certain amount of on-chip memory. On-chip memory is really one of two types: Internal RAM and Special Function Register (SFR) memory.
External Ram in 8051
As an obvious opposite of Internal RAM, the 8051 also supports what is called External RAM.
As the name suggests, External RAM is any random access memory which is found off-chip. Since the memory is off-chip it is not as flexible in terms of accessing, and is also slower. For example, to increment an Internal RAM location by 1 requires only 1 instruction and 1 instruction cycle. To increment a 1-byte value stored in External RAM requires 4 instructions and 7 instruction cycles. In this case, external memory is 7 times slower!
I.R.K.Seneviratne - Sri Lanka
Wiki User
∙ 12y ago
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What is difference between 89s52 and 8051?
internal and external memory
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4
What is the difference between microcontroller 8051 and avr atmega16?
avr is high speed cmpar to 8051.in 8051 there are less number of instructions
What is the external data memory capacity of 8051 and why?
65536 bytes, because the 8051 family has a 16 bit external address buss.
What is the difference between 8051 pic controllers and arm7 lpc2148?
architecture
Difference between 89s51 and 89s52?
89s51 and 89s52 both are same version of 8051 microcontroller
What is the difference between 8051 8031 8751?
The difference is that those MCUs that start with 80 are romless, those with 87 use EPROM erasable by light
What is psen pin in 8051?
Program Store Enable: The read strobe to external program memory.
Diff between 8086 and 8051?
35
Which are internal bit addressable RAM locations of 8051?
The 16 bytes (128 bits) at internal RAM locations 0x20-0x2F are bit-addressable.
What is difference between 8051 and AT89S52?
Intel introduced the MCS-51 family of microcontrollers in 1980 as an enhanced MCS-48. The 8051 is the main processor in this family, featuring 4K EPROM, 128 bytes of RAM, 2x 16-bit timer/counters, serial UART, 2x external active low interrupts that can either be level or edge triggered (falling edge only), RAM stack that can address the full RAM space, vectored interrupts, and 16-bit address/8-bit data front side bus. The 8051 also includes a dedicated address latch pin (ALE), dedicated external program ROM read strobe pin (PSEN), and an active low external access pin (EA). When EA is externally tied high, the 8051 executes code from its internal ROM while addressing instructions past the internal program ROM space addresses external ROM if present. All code execution takes place from external program ROM if EA is tied low. The 8051's 16-bit program counter and front side bus can address up to 65536 external memory addresses for compatibility with a total of 64K external program ROM space. The 8051 also has a read and write strobe available (P3.6/WR and P3.7/RD) for up to 64K of external RAM as well. The 8052 is the 8051's big brother. It is identical to the 8051, with the addition of 8KB on chip program ROM, a 3rd 16-bit timer/counter with 16-bit autoreload (this timer can also be used as the baud rate generator for the UART in 16-bit autoreload, making for a baud timer with greater resolution for more available baud rates with just about any crystal), and a capture module that works with timer 2. The 8052 also has an additional 128B of RAM, making for a total of 256 bytes of on chip RAM space. The upper 128 bytes of RAM can only be indirectly addressed. The AT89S52 is Atmel's derivative of the 8052. It is compatible with Atmel's In-System Programming (ISP) via an on chip SPI interface, which allows it to be programmed via Atmel's AT89ISP programmer while the MCU is in the target circuit.
What is the difference between 8051 and at89s52?
Intel introduced the MCS-51 family of microcontrollers in 1980 as an enhanced MCS-48. The 8051 is the main processor in this family, featuring 4K EPROM, 128 bytes of RAM, 2x 16-bit timer/counters, serial UART, 2x external active low interrupts that can either be level or edge triggered (falling edge only), RAM stack that can address the full RAM space, vectored interrupts, and 16-bit address/8-bit data front side bus. The 8051 also includes a dedicated address latch pin (ALE), dedicated external program ROM read strobe pin (PSEN), and an active low external access pin (EA). When EA is externally tied high, the 8051 executes code from its internal ROM while addressing instructions past the internal program ROM space addresses external ROM if present. All code execution takes place from external program ROM if EA is tied low. The 8051's 16-bit program counter and front side bus can address up to 65536 external memory addresses for compatibility with a total of 64K external program ROM space. The 8051 also has a read and write strobe available (P3.6/WR and P3.7/RD) for up to 64K of external RAM as well. The 8052 is the 8051's big brother. It is identical to the 8051, with the addition of 8KB on chip program ROM, a 3rd 16-bit timer/counter with 16-bit autoreload (this timer can also be used as the baud rate generator for the UART in 16-bit autoreload, making for a baud timer with greater resolution for more available baud rates with just about any crystal), and a capture module that works with timer 2. The 8052 also has an additional 128B of RAM, making for a total of 256 bytes of on chip RAM space. The upper 128 bytes of RAM can only be indirectly addressed. The AT89S52 is Atmel's derivative of the 8052. It is compatible with Atmel's In-System Programming (ISP) via an on chip SPI interface, which allows it to be programmed via Atmel's AT89ISP programmer while the MCU is in the target circuit.
