IN C LANGUAGE

In this experiment, we design and implement a 9S12DG256 -based digital system that contains an 8 -bit, bi-directional, binary counter

; and an 8 -bit, bi-directional, one -hot rotator. Both run at approximately 1 Hz by software-generated delay . The counting direction (upward or

downward) for the counter, and the rotating direction (left or right) for the rotator, are given respectively by logic signals provided by a 2-bit DIP switch: CNT_DIR: 0 for upward, and 1 for downward;ROT_DIR: 0 for left, and 1 for right.The state of the counter,and that of the rotator are displayed with two 8 -bit LED bars

It is recommended that you use Port A as the counter, and Port B as the rotator. Port K can be used for signals CNT_DIR, and ROT_DIR, respectively. Make sure that you configure the ports for general purpose I/O and that you get the data directions correct (e.g ., Port A should be configured as an 8 -bit output port) Programming Symbolic names should be used wherever possible to improve your programs readability. Portability should also be taken into account. The following symbolic names should be used . PRTA, PRTB, PRTK CNT_DIR, ROT_DIR

Psuedo Code ------------------------------------------

Configure Port A to be an 8-bit output port;

Configure Port B to be an 8-bit output port;

Initialize Port A to 0;

Initialize Port B such that only 1 bit is ON;

while (1) {

delay for the effect of soft clock;

read Port K;

if (CNT_DIR is 0)

increment Port A;

else

decrement Port A;

if (ROT_DIR is 0)

left-rotate Port B;

else

right-rotate Port B;

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Only got this much done.

DDRA = 0xFF;

PORTA = 0x00;

DDRB = 0xFF:

PORTB = 0x01;

DDRK = 0x00;

PORTK = 0xFF

for(;;){

CNT _ DIR = PORTK & 0x01;

ROT _ DIR = PROTK & 0x02;