User`s guide
MaxLoader User’s Guide
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programmable, the FPLA can implement some functions which a PAL or
PROM may not be able to implement.
EPLD: Several manufacturers produce PLDs which can be erased and
reprogrammed like EPROMs. These ICs are called erasable programmable
logic devices or EPLDs. Internally, they have the same programmable AND-
OR-register structures of the PAL and FPLA.
Microcontroller
These devices are CPU's with on-chip EPROM and RAM. They are typically
40 pins and are UV erasable. They have part numbers such as Intel's
8748,8749,8751,8752 etc. A micro-controller is generally a computer-on-a-chip
with RAM, ROM, and I/O ports. Microcontrollers are usually used for specific
purposes, such as keyboard decoders, printers, clocks, telephones, CD-players,
or any other application that requires a small, on-board computer.
Microcontrollers are used to take the place of in-circuit logic, as it can be less
expensive and take less space. Also, since it is software driven, the device may
be updated very easily. Micro-controllers have the ability to use internal as well
as external RAM. Also, micro-controller data may be encrypted or otherwise
secured to prevent copying of the data or program information. Microcontrollers
also have their own instruction set, usually very similar to familiar
Microprocessors (such as the 8080 or 8086). The INTEL MCS-51 family
features up to 64k each of internal and external memory, 32 I/O lines,
interrupts, timers, and bit-addressable RAM. Its instruction set contains 111
instructions. However, for specific purposes, limited versions of the 51 family
are available. For instance, the Philips 87c751/87c752 families do not allow
external RAM to be used, and have limited I/O channels, etc. However, these
devices still allow for data/program encryption and security levels. They are
also less expensive than the MCS-51 micro-controllers.
See the help selection under MAIN-MENU COMMANDS for Encryption and
Security-bit information.