Abstract:
The main objective of this paper is to
implement a control unit for the 16 bit CPU used in
Microprocessor Trainer. In Microprocessor Trainer,
there are six modules and they are connected by the
address bus (A [0...15]), the data bus (D [0...15]) and
the control buses (MEMWR, MEMRD, IOWR and
IORD). The modules involved in Microprocessor
Trainer are CPU module, DMA module, Memory
module, I/OCPU module, I/O Interface module and
power supply. The Microprocessor Trainer uses 16-
bit wide instruction sets. The whole module is
supplied +5V DC from the power supply. The control
unit is responsible for instruction fetching, decoding,
executing, generating control signals such as
MEMWR, MEMRD, IOWR, IORD etc. Control unit of
this paper consists of following data transfer and
program control instructions: Move, Store Word,
Load Word, Load Halfword, Branch on equal,
Branch on not equal, Branch on zero, Branch on not
zero, Branch Greater than, Branch Less than, Jump,
Call, Return, In, Out and Halt. All operations are
controlled by using PIC 18F452 microcontroller. The
control microprogram is developed with assembly
language to control the operation precisely and to
minimize the clock cycle
