Motorola MPC564EVB Manuel d'utilisateur télécharger pdf (Page 90)

3-40 MPC564EVB User’s Manual

System Call Functions

{ /* assume r3 contains the character */

asm(“ addi r10, r0, 0x0000”); Selects the function

asm(“ sc”); The character is returned in r3

}

3.5.3 IN_STAT

This function (function code 0x0001) checks if an input character is present to receive. A value of

zero is returned in r3 when no character is present. A value of 1 in r3 means a character is present.

Assembly example:

addi r10, r0, 0x0001 Select the function

sc Make the call, r3 contains the response (yes/no).

C example:

int board_char_present (void)

{

asm( "addi r10,r0,0x0001");Select the function

asm( "sc"); Make the call, r3 contains the response (yes/no).

}

3.5.4 ISR_REGISTER

This function’s code is 0x0040. For ISR_REGISTER, the vector, handler, device ptr, and arg ptr

are in r3, r4, r5, and r6 respectively.

C example:

int

board_isr_register (int vector, void *handler, void *device, void *arg)

{

* Vector will normally be 0x0500 for IRQ. Handler should be address

* of your routine. Device and Arg are both used as arguments to

* Handler when it is invoked. Ie. handler(device,arg); It is

* intended that Device point to the device. If the handler is

* registered OK, 1 is returned, otherwise 0.

asm( "addi r10,r0,0x0040");

asm( "sc");

}

3.5.5 ISR_REMOVE

This function’s code is 0x0041. For ISR_REMOVE, the vector is in r3. Nothing is returned.

Assembly example:

addi r10, r0, 0x0041 Selects the function

sc The character is returned in r3

Frees

cale Semiconductor,

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

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Motorola MPC564EVB Manuel d'utilisateur Page 90

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