NXP Flash MCU to Atmel Flash MCU Cross Reference. 07/01/ 86KB. NXP Flash MCU to Atmel Flash MCU Devices, Non-Direct Replacements. 07/01/ The device is manufactured using Atmel’s high density nonvolatile memory technology and is compatible with the industry standard 80C51 instruction set and. 89C55 datasheet, 89C55 circuit, 89C55 data sheet: ATMEL – 8-Bit Microcontroller with 20K Bytes Flash,alldatasheet, datasheet, Datasheet search site for.
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Otherwise, the pin is weakly pulled high. RXD serial input port. In this application, Port 2 uses strong internal pul- lups when emitting 1s. External pullups are required during program verifica- tion. When 1s are written to Port 2 pins, they are pulled high by the 89cc55 pullups and can be used as inputs. Port 3 also receives the highest-order address bit and some control signals for Flash programming and verifica- tion.
AT89C55WD – Microcontrollers and Processors – Microcontrollers and Processors
INT1 external interrupt 1. For example, the following indirect addressing instruction, where R0 contains 0A0H, accesses 89c555 data byte at address 0A0H, rather than P2 whose address is 0A0H. Instructions that use indirect addressing access the upper bytes of RAM. TXD serial output port.
T0 timer 0 external input.
T1 timer 1 external input. Instructions that use direct addressing access SFR space. Two priorities can be set for each of the six interrupt sources in the IP register. When 1s are written to Port 3 pins, they are pulled high by the internal pullups and can 89c5 used as inputs. RD external data memory read strobe. Setting the ALE-disable bit has no effect if the microcontroller is in external execution mode.
89C55 Datasheet(PDF) – ATMEL Corporation
Note 89c5 stack operations are examples of indirect addressing, so the upper bytes of data RAM are avail- able as stack space. In tamel case, the reset or inactive values of the new bits will always be 0. Note, however, that one ALE pulse is skipped during each access to external data mem- ory. As inputs, Port 2 pins that are externally being pulled low will source current I. Interrupt Registers The individual interrupt enable bits are in the IE register.
The device is manu- factured using Atmel’s high density nonvolatile memory technology and is compatible with the industry standard 80C51 instruction set and pinout. This pin also receives the volt programming enable volt- age V. Three-Level Program Memory Lock.
When 1s are written to port 0 pins, the pins can be used as high- impedance inputs. The AT89C55 provides the following standard features: WR external data memory write strobe. As inputs, Port 3 pins that are externally being pulled low will source current I. A high on this pin for two machine cycles while the oscillator is running resets 98c55 device.
As an output port, each pin can sink eight TTL inputs.
At89c55-24jc Atmel IC Microcontroller 8-bit 44 Pin PLCC MCU 89c55-24jc
Port 1 also receives the low-order address bytes during Flash programming and verification. Note, however, that if lock bit 1 is programmed, EA will be internally latched on reset.
The low-voltage option saves power and operates with a 2. EA should be strapped to V. The on-chip Flash allows the program memory to be reprogrammed in-system or by a conventional nonvolatile memory programmer. As inputs, Port 1 pins that are externally being pulled low will source current I. INT0 external interrupt 0.
User software should not write 1s to these unlisted loca- tions, since they may be used in future products to invoke new features. In addition, the AT89C55 is designed with static logic atmdl operation down to zero frequency and sup- ports two software selectable power saving modes.
The upper bytes occupy a parallel address space to the Special Function Registers. By combining a versatile 8-bit CPU with Flash on a monolithic chip, the Atmel AT89C55 is a powerful microcomputer which provides a highly flexible and cost effective solution to many embedded control applications. Read stmel to these addresses will in general return random data, and write atmep will have an indetermi- nate effect. Port 2 also receives the high-order address bits and some control signals during Flash programming and verification.