Cirrus Logic AN118 - Manual (Page 24)

AN118
24 AN118REV2
sample_size = 1;
break;
default:
sample_size = 0;
break;
}
} /* END decode_sample_index */
/**************************************************************/
/* Routine - test_mode
*/
/* Input - none */
/* Output - none */
/* Description - This routine is used to perform special test */
/* functions to aid in debugging the CDB hardware. */
/**************************************************************/
void test_mode(){
switch (temp) {
/* Test Mode 1: For this test, user must place HDR7 into
loop back position. A byte of data is sent out UART
of 80C51 and received at same time. It the byte
that is returned is the same all LEDs toggle.
Otherwise, only half the LEDs toggle. */
case 0x01:
RESET = 0x00; /* Set LED Indicator */
TXSER(0xAA);
low_byte = RXSER();
/* low byte first*/
Delay();
if(low_byte == 0xAA)
toggle_all_leds(); /* Test Passed */
else
toggle_two_leds(); /* Test Failed */
break;
/* Test Mode 2: This test mode writes to the offset and gain
registers of PC1. It then reads the registers.
If the correct data is read back all the LED’s toggle
otherwise only half of them toggle to indicate an error. */
case 0x02:
COMM = 0x01;
write_to_register(0x01,0x00,0x00,0xAA); /* Write Offset PC1 */
write_to_register(0x02,0x00,0x00,0xAA); /* Write Gain PC1 */
read_register(0x09);
/* Read Offset PC1 */
if(high_byte ==0xAA){ /* Was data sent? */
read_register(0x0A); /* Read Gain PC1 */
if(high_byte==0xAA)
toggle_all_leds();
else
toggle_two_leds(); /* Test Failed */
} /* END if */