Syntax
void SHIFTOUT (int out_pin, int
clk_pin, int mode, int cnt , int *wordList,
int bitLengths) ;
Description
SHIFTOUT has been kept as a compatable function with
PBASIC. It can be used for devices that are not covered by SPI, I2C or
1-Wire. Data is placed on
out_pin and the
clk_pin is pulsed
each bit.
While most other hardware functions use bytes, SHIFTOUT is oriented for bit
control. The length of each variable defines the number of bits that will
be shifted out (2 - 32). For each element bitLengths bits are
shifted out.
- Mode = 0 data is shifted out LSB first
- Mode = 1 data is shifted out MSB first
SHIFTOUT uses values from the interger array wordList. cnt
integers will be shifted out.
Data is shifted out of the device at 800 Kbits/sec.
Example
printf("FPU SHIFT test\n");
for (i= 0; i<10; i++) wordMessage[i]=
0xFF;
wordMessage [i] =
0;
SHIFTOUT (14,15,MSBFIRST,11,wordMessage,
8); // reset FPU
WAIT
(10); wordMessage [0] =
0xF0; // sync
character
SHIFTOUT (14,15,MSBFIRST,1,wordMessage,
8); // sync FPU
save_time =
TIMER;
while ((TIMER - save_time) < 15)
; // wait 15
uSec
SHIFTIN (14,15,
MSBPRE, 1,wordMessage, 8); // get 1 byte status
back
if (wordMessage[0] != 0x5C)
{
printf("%x No FPU
found\n",shortResponse[0]); break;
}
printf("FPU found\n");
See also
