In the process of Break Microprocessor W78E052 Locked Program, first of all we should have a general understanding about Microprocessor W78E052.
The W78E052 is an 8-bit microcontroller which has an in-system programmable MTP-ROM for firmware updating. The instruction set of the W78E62B is fully compatible with the standard 8052. The W78E052 contains a 64K bytes of main MTP-ROM and a 4K bytes of auxiliary MTP-ROM which allows the contents of the 64KB main MTP-ROM to be updated by the loader program located at the 4KB auxiliary MTP-ROM;
512 bytes of on-chip RAM; four 8-bit bi-directional and bit-addressable I/O ports; an additional 4-bit port P4; three 16-bit timer/counters; a serial port. These peripherals are supported by a eight sources two-level interrupt capability.
To facilitate programming and verification, the MTP-ROM inside the W78E052 allows the program memory to be programmed and read electronically after Break Microprocessor W78E052 Locked Program. Once the code is confirmed, the user can protect the code for security.
The W78E052 microcontroller has two power reduction modes, idle mode and power-down mode, both of which are software selectable. The idle mode turns off the processor clock but allows for continued peripheral operation.
The power-down mode stops the crystal oscillator for minimum power consumption. The external clock can be stopped at any time and in any state without affecting the processor.
Fully static design 8-bit CMOS microcontroller up to 40
64K bytes of in-system programmable MTP-ROM for Application Program (APROM).
4K bytes of auxiliary MTP-ROM for Loader Program (LDROM).
Low standby current at full supply before Break Microprocessor W78E052 Locked Program
512 bytes of on-chip RAM. (including 256 bytes of AUX-RAM, software selectable)
64K bytes program memory address space and 64K bytes data memory address
Four 8-bit bi-directional
One 4-bit multipurpose programmable
Build-in 74373 and 74244 logical functions on Port 2.(software programmable)
Three 16-bit timer/counters
One full duplex serial port
Eight-sources, two-level interrupt capability
Built-in power management
Code protection
Port 4, SFR P4 at address D8H, is a 4-bit multipurpose programmable I/O port. Each bit can be configured individually by software. The Port 4 has four different operation mode:
In mode 0, P4.0-P4.3 is a bi-directional I/O port which is same as port 1. P4.2 and P4.3 also serve as external interrupt INT3 and INT2 if enabled.
In mode 1, P4.0-P4.3 are read data strobe signals which are synchronized with RD signal at specified addresses. These signals can be used as chip-select signals for external peripherals.