HT48R50A-1/HT48C50-1
Bit Operations
Other Operations
The ability to provide single bit operations on Data Mem-
ory is an extremely flexible feature of all Holtek
microcontrollers. This feature is especially useful for
output port bit programming where individual bits or port
pins can be directly set high or low using either the ²SET
[m].i² or ²CLR [m].i² instructions respectively. The fea-
ture removes the need for programmers to first read the
8-bit output port, manipulate the input data to ensure
that other bits are not changed and then output the port
with the correct new data. This read-modify-write pro-
cess is taken care of automatically when these bit oper-
ation instructions are used.
In addition to the above functional instructions, a range
of other instructions also exist such as the ²HALT² in-
struction for Power-down operations and instructions to
control the operation of the Watchdog Timer for reliable
program operations under extreme electric or electro-
magnetic environments. For their relevant operations,
refer to the functional related sections.
Instruction Set Summary
The following table depicts a summary of the instruction
set categorised according to function and can be con-
sulted as a basic instruction reference using the follow-
ing listed conventions.
Table Read Operations
Table conventions:
Data storage is normally implemented by using regis-
ters. However, when working with large amounts of
fixed data, the volume involved often makes it inconve-
nient to store the fixed data in the Data Memory. To over-
come this problem, Holtek microcontrollers allow an
area of Program Memory to be setup as a table where
data can be directly stored. A set of easy to use instruc-
tions provides the means by which this fixed data can be
referenced and retrieved from the Program Memory.
x: Bits immediate data
m: Data Memory address
A: Accumulator
i: 0~7 number of bits
addr: Program memory address
Mnemonic
Arithmetic
Description
Cycles Flag Affected
ADD A,[m]
ADDM A,[m]
ADD A,x
Add Data Memory to ACC
1
1Note
1
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
Z, C, AC, OV
C
Add ACC to Data Memory
Add immediate data to ACC
ADC A,[m]
ADCM A,[m]
SUB A,x
Add Data Memory to ACC with Carry
1
1Note
Add ACC to Data memory with Carry
Subtract immediate data from the ACC
Subtract Data Memory from ACC
1
SUB A,[m]
SUBM A,[m]
SBC A,[m]
SBCM A,[m]
DAA [m]
1
1Note
Subtract Data Memory from ACC with result in Data Memory
Subtract Data Memory from ACC with Carry
Subtract Data Memory from ACC with Carry, result in Data Memory
Decimal adjust ACC for Addition with result in Data Memory
1
1Note
1Note
Logic Operation
AND A,[m]
OR A,[m]
XOR A,[m]
ANDM A,[m]
ORM A,[m]
XORM A,[m]
AND A,x
Logical AND Data Memory to ACC
Logical OR Data Memory to ACC
Logical XOR Data Memory to ACC
Logical AND ACC to Data Memory
Logical OR ACC to Data Memory
Logical XOR ACC to Data Memory
Logical AND immediate Data to ACC
Logical OR immediate Data to ACC
Logical XOR immediate Data to ACC
Complement Data Memory
1
1
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
Z
1
1Note
1Note
1Note
1
OR A,x
1
XOR A,x
1
1Note
CPL [m]
CPLA [m]
Complement Data Memory with result in ACC
1
Increment & Decrement
INCA [m]
INC [m]
Increment Data Memory with result in ACC
1
Z
Z
Z
Z
Increment Data Memory
1Note
DECA [m]
DEC [m]
Decrement Data Memory with result in ACC
Decrement Data Memory
1
1Note
Rev. 2.01
21
January 9, 2009
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
