topic Re: How to AND the accumulator in 8-bit Microcontrollers

How to AND the accumulator

theGhost — Wed, 26 Oct 2011 05:22:47 GMT

Hello,

I have a GT16A, HCSO8 familly.

I want to AND the accumulator.

ANDing two ports is easy. eg: AND PTAD, PTBD

But How do you AND the accunulator with a value (eg: #$AA) or with value in memory or with a port?

Thank you for your help.

Re: How to AND the accumulator

peg — Thu, 29 Oct 2020 09:26:10 GMT

Hello the Ghost,

The AND instruction ALWAYS AND's with the accumulator!

The example you show is not valid.

One way to perform your example is:

LDA PTAD

AND PTBD

Your other question would be:

LDA #$AA

AND PTAD

Here is the instruction from the manual:

AND Logical AND ANDOperation A ← (A) & (M)Description Performs the logical AND between the contents of A and the contents ofM and places the result in A. Each bit of A after the operation will be thelogical AND of the corresponding bits of M and of A before the operation.Condition Codesand BooleanFormulae:V: 0ClearedN: R7Set if MSB of result is 1; cleared otherwiseZ: R7&R6&R5&R4&R3&R2&R1&R0Set if result is $00; cleared otherwiseSource Forms,AddressingModes, MachineCode, Cycles, andAccess DetailsV H I N Z C0 1 1 — — ↕ ↕ —SourceFormAddr.ModeMachine Code HCS08CyclesAccessOpcode Operand(s) DetailAND #opr8i IMM A4 ii 2 ppAND opr8a DIR B4 dd 3 rppAND opr16a EXT C4 hh ll 4 prppAND oprx16,X IX2 D4 ee ff 4 prppAND oprx8,X IX1 E4 ff 3 rppAND ,X IX F4 3 rfpAND oprx16,SP SP2 9ED4 ee ff 5 pprppAND oprx8,SP SP1 9EE4 ff 4 prppFreescale Semiconductor, IFreescale Semiconductor, Inc.For More Information On This Product,Go to: www.freescale.comnc

Re: How to AND the accumulator

rocco — Wed, 26 Oct 2011 05:49:29 GMT

Hi Ghost,

You misunderstand, " AND PTAD, PTBD" is not a valid instruction in the S08. It should be giving you a syntax error.

The AND instruction ONLY works with the accumulator. To AND the immediate value $AA to the accumulator, the instruction would be " AND #$AA". To AND the contents of memory to the accumulator, the instruction would be "AND <address>", regardless of whether <address> is flash, ram or a port. There is no instruction to AND directly to memory or a port.

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Oops: I see Peg and I cross-posted.