UPSD3212A(2009) Просмотр технического описания (PDF) - STMicroelectronics

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UPSD3212A
(Rev.:2009)

Flash programmable system devices with 8032 MCU and USB and programmable logic

STMicroelectronics 

Architecture overview

UPSD3212A, UPSD3212C, UPSD3212CV

2.10

Note:

Logical instructions

Table 5 lists logical instructions for UPSD321xx devices. The instructions that perform

Boolean operations (AND, OR, Exclusive OR, NOT) on bytes perform the operation on a bit-

by-bit basis. That is, if the Accumulator contains 00110101B and byte contains 01010011B,

then:

ANL A, <byte>

will leave the Accumulator holding 00010001B.

The addressing modes that can be used to access the <byte> operand are listed in Table 5.

The ANL A, <byte> instruction may take any of the forms:

ANL A,7FH(direct addressing)

ANL A, @R1 (indirect addressing)

ANL A,R6 (register addressing)

ANL A,#53H (immediate constant)

Boolean operations can be performed on any byte in the internal Data Memory space

without going through the Accumulator. The XRL <byte>, #data instruction, for example,

offers a quick and easy way to invert port bits, as in:

XRL P1, #0FFH.

If the operation is in response to an interrupt, not using the Accumulator saves the time and

effort to push it onto the stack in the service routine.

The Rotate instructions (RL A, RLC A, etc.) shift the Accumulator 1 bit to the left or right. For

a left rotation, the MSB rolls into the LSB position. For a right rotation, the LSB rolls into the

MSB position.

The SWAP A instruction interchanges the high and low nibbles within the Accumulator. This

is a useful operation in BCD manipulations. For example, if the Accumulator contains a

binary number which is known to be less than 100, it can be quickly converted to BCD by

the following code:

MOVE B,#10

DIV AB

SWAP A

ADD A,B

Dividing the number by 10 leaves the tens digit in the low nibble of the Accumulator, and the

ones digit in the B register. The SWAP and ADD instructions move the tens digit to the high

nibble of the Accumulator, and the ones digit to the low nibble.

Table 5. Logical instructions

Mnemonic

Operation

ANL A,<byte>

ANL <byte>,A

ANL <byte>,#data

ORL A,<byte>

A = A .AND. <byte>

A = <byte> .AND. A

A = <byte> .AND. #data

A = A .OR. <byte>

Addressing modes

Dir.

Ind.

Reg.

Imm.

X

X

X

X

X

X

X

X

X

X

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