Hello:

I'm deveoping a simple IO driver for the Renesas 78K0R family of microcontrollers.

For now I have 2 functions:

bool Get_Port (unsigned char port_id, unsigned char pin_mask)

void Set_port (unsigned char port_id, unsigned char pin_mask, bool value).

For example in the Set_port function I have a switch case which checks for all the ports that belong to this micro, something like:

#define PORT1 0
#define PORT2 1

switch(port_id):

case PORT1:
value == TRUE? (P1|=pin_mask1 &= ~pin_mask);
case PORT2:
value == TRUE? (P2|=pin_mask2 &= ~pin_mask);
.
.
.
.

As you can see the logic is very simple. If for example I want to turn on a LED I just pass a value of 1. If I want to turn it off I pass a value of 0.

Is there any way to make the port number as a parameter so I don't have to use a lot of switch..case statements?

Otherwise if I have 10 different ports I will have to create 10 different switch..case statements.

Thanks and help is greatly appreciated

 

Use a (shift with a and/or) mask to set or clear the bits.

http://en.wikipedia.org/wiki/Mask_(computing)

Use the bitwise OR operator (|) to set a bit.
number |= 1 << x;

Use the bitwise AND operator (&) to clear a bit.
number &= ~(1 << x);

 

Use a (shift with a and/or) mask to set or clear the bits.

http://en.wikipedia.org/wiki/Mask_(computing)

Use the bitwise OR operator (|) to set a bit.
number |= 1 << x;

Use the bitwise AND operator (&) to clear a bit.
number &= ~(1 << x);

That's something similar of what I'm doing if you look at my first post.

pin_mask already has the proper masks so no need to add the extra 1 when doing the shifting.

e.g. 0x01, 0x02, 0x04, 0x08, 0x10, 0x20 etc.

P1 and P2 are microcontroller specific IO registers for the Renesas 78K0R defined in a header file.

My main question is how can I code a function that would take as a parameter a specific register?

If there are 50 ports I will have to code 50 switch..case statements which makes the code not very portable and practical.

The type of those registers in the header file is not a simple data type like usigned char but some weird types that start with ___.

Thanks

 

That's what I'm doing if you look at my first post.

P1 and P2 are microcontroller specific IO registers for the Renesas 78K0R defined in a header file.

My main question is how can I code a function that would take as a parameter a specific register?

The type of those registers in the header file is not a simple data type like usigned char but some weird types that start with ___.

Thanks

If it's a memory-mapped register you can use pointers with the address of the register as a parameter.

http://www.embedded.com/electronics-blogs/programming-pointers/4025002/Mapping-memory
http://www.embedded.com/electronics...nters/4208573/Accessing-memory-mapped-classes

 

If it's a memory-mapped register you can use pointers with the address of the register as a parameter.

http://www.embedded.com/electronics...nters/4208573/Accessing-memory-mapped-classes

I already tried that but it does not work.

The LED's won't turn on.

Hopefully that article will shed some light.

Thanks and will report back if I still have problems.

 

I already tried that but it does not work.

The LED's won't turn on.

Hopefully that article will shed some light.

Thanks and will report back if I still have problems.

That should work if you are passing the correct type pointer and using a deref to access the actual data at that pointer address. Make sure any pointers are "volatile" as your compiler might optimize the code to nothing otherwise.