Forums

Problems configuring PAD0..15 as input

Started by silvozemljic May 14, 2004

Hello.
I'm using Adapt9S12E128 Microcontroller Module with MC9S12E128CPV
chip.
and Metrowerks Codewarrior development environment for HCS12 chips.
Here is my problem...
I would like to use PAD0..15 lines which are conected to onchip ATD
module as inputs, so that I can generate external interrupts on AD
port.
So I do following...
- set appropriate bits in ATDDIEN0 and ATDDIEN1 registers (ATD Input
Enable Registers) in ATD module to 1 (so I enable digital input on
those lines)
- if I understand ATD Block Guide correctly, ATD module is in power
off state at startup or reset, anyway, and I don't use ATD module at
this point
- next I set Port AD registers... appropriate bit in Data Direction
Register (DDARD) to 0 (configure it as input) and set all other
interrupt related registers

So, in this configuration all the changes to signals on PAD0..15
lines should reflect in Port Data Registers (PORTAD0 and PORTAD1) of
ATD module and
if I understand several Guides correctly also in Port AD I/O Register
(PTAD) and also in Port AD Input Register (PTIAD).
But when I change the level of the signals on PAD pins the change is
only reflected in ATD module PORTAD0 and PORTAD1, but not in the AD
Port registers.

I've studied all the appropriate guides, but cannot find my error. Am
I missing something here? Can anybody help me? I woul really
appreciate it, because
I'm out of ideas and I really started to like this huge world of
small microcontrollers. I would appreciate any kind of help.

Thank you in advance for your effort and have a nice weekend.

Silvo Zemljic



Silvo,

I am currently working with the E128 and I had a similar problem.

The I/O registers for Port AD are 16-bit registers and MUST be
accessed as such. You cannot access the high and low addresses
independently. I wish this was more clear in the documentation.

In C, you should declare the register as a pointer to unsigned
short int. For example:

#define ioPortAD (*(volatile unsigned short int *)(ADDRESS))

Hope this helps.

Chris Knight -----Original Message-----
From: silvozemljic [mailto:]
Sent: Friday, May 14, 2004 5:26 AM
To:
Subject: [68HC12] Problems configuring PAD0..15 as input Hello.
I'm using Adapt9S12E128 Microcontroller Module with MC9S12E128CPV
chip.
and Metrowerks Codewarrior development environment for HCS12 chips.
Here is my problem...
I would like to use PAD0..15 lines which are conected to onchip ATD
module as inputs, so that I can generate external interrupts on AD
port.
So I do following...
- set appropriate bits in ATDDIEN0 and ATDDIEN1 registers (ATD Input
Enable Registers) in ATD module to 1 (so I enable digital input on
those lines)
- if I understand ATD Block Guide correctly, ATD module is in power
off state at startup or reset, anyway, and I don't use ATD module at
this point
- next I set Port AD registers... appropriate bit in Data Direction
Register (DDARD) to 0 (configure it as input) and set all other
interrupt related registers

So, in this configuration all the changes to signals on PAD0..15
lines should reflect in Port Data Registers (PORTAD0 and PORTAD1) of
ATD module and
if I understand several Guides correctly also in Port AD I/O Register
(PTAD) and also in Port AD Input Register (PTIAD).
But when I change the level of the signals on PAD pins the change is
only reflected in ATD module PORTAD0 and PORTAD1, but not in the AD
Port registers.

I've studied all the appropriate guides, but cannot find my error. Am
I missing something here? Can anybody help me? I woul really
appreciate it, because
I'm out of ideas and I really started to like this huge world of
small microcontrollers. I would appreciate any kind of help.

Thank you in advance for your effort and have a nice weekend.

Silvo Zemljic


Set these registers then check each bit flag after an interrupt

movb #$FF,ATDDIEN0 ;Enable ATD channel as Digital input
movb #$00,DDRADH ;make Port ADH i/p
movw #$FFFF,PERADH ;Enable pullup

movb #$00,PPSADH ;Interrupt on falling edge
movb #$FF,PIEADH ;Enable interrupt TestATDHInt
brset PIFADH,%00000001,Int8
brset PIFADH,%00000010,Int9
brset PIFADH,%00000100,Int10
brset PIFADH,%00001000,Int11
brset PIFADH,%00010000,Int12
brset PIFADH,%00100000,Int13
brset PIFADH,%01000000,Int14
brset PIFADH,%10000000,Int15 --- In , "Chris Knight" <knight@h...> wrote:
> Silvo,
>
> I am currently working with the E128 and I had a similar problem.
>
> The I/O registers for Port AD are 16-bit registers and MUST be
> accessed as such. You cannot access the high and low addresses
> independently. I wish this was more clear in the documentation.
>
> In C, you should declare the register as a pointer to unsigned
> short int. For example:
>
> #define ioPortAD (*(volatile unsigned short int *)(ADDRESS))
>
> Hope this helps.
>
> Chris Knight > -----Original Message-----
> From: silvozemljic [mailto:silvo.zemljic@h...]
> Sent: Friday, May 14, 2004 5:26 AM
> To:
> Subject: [68HC12] Problems configuring PAD0..15 as input > Hello.
> I'm using Adapt9S12E128 Microcontroller Module with MC9S12E128CPV
> chip.
> and Metrowerks Codewarrior development environment for HCS12 chips.
> Here is my problem...
> I would like to use PAD0..15 lines which are conected to onchip ATD
> module as inputs, so that I can generate external interrupts on AD
> port.
> So I do following...
> - set appropriate bits in ATDDIEN0 and ATDDIEN1 registers (ATD
Input
> Enable Registers) in ATD module to 1 (so I enable digital input on
> those lines)
> - if I understand ATD Block Guide correctly, ATD module is in power
> off state at startup or reset, anyway, and I don't use ATD module
at
> this point
> - next I set Port AD registers... appropriate bit in Data Direction
> Register (DDARD) to 0 (configure it as input) and set all other
> interrupt related registers
>
> So, in this configuration all the changes to signals on PAD0..15
> lines should reflect in Port Data Registers (PORTAD0 and PORTAD1)
of
> ATD module and
> if I understand several Guides correctly also in Port AD I/O
Register
> (PTAD) and also in Port AD Input Register (PTIAD).
> But when I change the level of the signals on PAD pins the change
is
> only reflected in ATD module PORTAD0 and PORTAD1, but not in the AD
> Port registers.
>
> I've studied all the appropriate guides, but cannot find my error.
Am
> I missing something here? Can anybody help me? I woul really
> appreciate it, because
> I'm out of ideas and I really started to like this huge world of
> small microcontrollers. I would appreciate any kind of help.
>
> Thank you in advance for your effort and have a nice weekend.
>
> Silvo Zemljic