8-bit MicrocontrollersのトピックOpen input pins can avoid with on chip pullup enable. E.g. for MS9S08QG8 must set Register PTBPE on

Open input pins can avoid with on chip pullup enable. E.g. for MS9S08QG8 must set Register PTBPE on

Mei — Wed, 11 Nov 2020 12:18:39 GMT

Open input pins can avoid with on chip pullup enable. E.g. for MS9S08QG8 must set Register PTBPE on addess 0x1844.

But I can't see reaction of write: mov $ff, PTBPE.
I don't see any change to address $ 1840 while debugging, nor do I see defined levels on the B ports.
Programs with MC68HC08QT implemented a measurable internal resistance to + (VDD) at Pullupenable.

Can You help?

With best regards
Gerd

Re: Open input pins can avoid with on chip pullup enable. E.g. for MS9S08QG8 must set Register PTBPE

vicentegomez — Thu, 12 Nov 2020 23:01:40 GMT

Can you confirm, please?

Should be check address 0x1844 not 0x1840

There is a sample code in ASM on the codewarrior samples code, you can use them as reference, normally is on the following folder

C:\...\CW MCU v11.1\MCU\CodeWarrior_Examples\HC_Examples\mc9s08qg8_demo

Regards

Vicente

Re: Open input pins can avoid with on chip pullup enable. E.g. for MS9S08QG8 must set Register PTBPE

Mei — Fri, 20 Nov 2020 17:17:54 GMT

Dear Vicente,

thank you for your replay.

Yes, you are right. PTBPE must set in 0x1844.

But that wasn't the real mistake. Now I've found my mistake:

In my question I wrote: "But I can't see reaction of write: mov $ff, PTBPE."

Command --"mov $FF, PTBPE" -- is not suitable for setting the PTBPE register in 16 Bit address 0x1844, (High Page Registers)

Operand must be an 8 bit address in Direct Page Registers in lower address area.

E.g. PTBDD can be set with mov # $ FF, PTBDD.

In the case of PTBPE, I should have written: lda # $ FF sta PTBPE. Above the # sign was also missing.

I apologize for these simple assembler programming problems.

With best regards

Gerd Meinert