Triggering 5 TTL clocks simultaneously

[TurboLS]

OK, this code is written to wait for an interrupt, then clock out 784x512 bytes of data. The only chunk of the code shown is that which controls the clocking scheme. My question is if there is any way to execute time sensitive commands faster than the 1 usec instruction time. Thanks for all the help.

horizpulse var byte
vertpulse var byte

horizpulse = 1
vertpulse = 1
PORTB.0 = 0 ‘portb.0 is the Vphase1 clock
PORTB.1 = 0 ‘portb.1 is the Vphase2 clock
PORTB.2 = 1 ‘portb.2 is the Hphase1 clock
PORTB.3 = 0 ‘portb.3 is the Hphase2 clock
PORTB.4 = ‘portb.4 is the reset clock

buttonloop:
IF PushButtonOnPORTABIT2 = 1
THEN GOTO vertloop ‘waits for 5V that signals shutter is closed
ELSE GOTO buttonloop
vertloop:
horizpulse = 1
PORTB.0 = 1
PAUSEUS 139
PORTB.0 = 0
PORTB.1 = 1
PAUSEUS 139
PORTB.0 = 1
PORTB.1 = 0
PAUSEUS 139
PORTB.0 = 0
PAUSEUS 270
vertpulse = vertpulse + 1
IF vertpulse < 512
THEN GOTO horizloop
ELSE GOTO buttonloop
horizloop:
PORTB.2 = 0
PORTB.3 = 1
PAUSEUS 139
PORTB.3 = 0
PORTB.2 = 1
PAUSEUS 139
horizpulse = horizpulse + 1
IF horizpulse < 784
THEN GOTO horizloop
ELSE GOTO vertloop
END

[mister_e]

My question is if there is any way to execute time sensitive commands faster than the 1 usec instruction time

use a faster crystal.. depending of your PIC... some can run up to 40MHZ.

so in this case... 0.1 usec by SOME ASSEMBLER instruction

[TurboLS]

I was also toying with the idea of just setting the registers in one line, like

PORTA = %11001010

or something to that effect, but I have no idea how I would loop that.

[mister_e]

if you want to send 8 bits of data to PORTA in one shot... yes PORTA=MydataToSend will be what you need. Be sure that you have set the TRISA register before that
TRISA=255

[TurboLS]

Ok, here is my updated code, now I just have a few questions:

1.) Is there a way to split PORTA into analog and digital inputs?
2.) PORTB.4 is the reset clock and basically it has to be pulsing as soon as the microcontroller powers up. The problem is that once i start the other clocks, the time at which the reset goes high has to be in synch with H1 going low and H2 going high. In addition, it's high duration is 1/4 of the high time of the horizontal clocks. I will post up a timing diagram to explain what i mean later today. So basically I can't just put it in one of my loops, I have to start it pulsing at like a 25% duty cycle and when the other clocks are going, it has to be in synch with the horiztonals like i said earlier.

any help is appreciated.

' Connect analog input to (RA0)
' Connect clocks to PORTB
' PORTB.0 is the Vphase1 clock
' PORTB.1 is the Vphase2 clock
' PORTB.2 is the Hphase1 clock
' PORTB.3 is the Hphase2 clock
' PORTB.4 is the reset clock
' Connect pin 2 from the DB9 connector to PORTC.6
' Have a +5V source ready to touch PORTA.2 to trigger clocking process

include "modedefs.bas"

' Define ADCIN parameters
Define ADC_BITS 8 ' Set number of bits in result
DEFINE OSC 20 ' Sets clock speed to 20Mhz
Define ADC_CLOCK 4 ' Set clock source (3=rc)
Define ADC_SAMPLEUS 50 ' Set sampling time in uS

TRISA = %11111111 ' Set PORTA to all input
ADCON1 = %00000010 ' Set PORTA analog
TRISB = %00000000 ' Set PORTB to all output
Pause 500 ' Wait .5 second

Pause 500 ' Wait .5 second

horizpulse var byte
vertpulse var byte
adval var byte ' Create adval to store result

horizpulse = 1 ' Initialize counters, initial states
vertpulse = 1
PORTB.0 = 0
PORTB.1 = 0
PORTB.2 = 1
PORTB.3 = 0
PORTB.4 = 0

buttonloop:
IF PushButtonOnPORTABIT2 = 1
THEN GOTO vertloop ' Waits for 5V that signals shutter is closed
ELSE GOTO buttonloop
vertloop:
horizpulse = 1
PORTB.0 = 1
PAUSEUS 139
PORTB.0 = 0
PORTB.1 = 1
PAUSEUS 139
PORTB.0 = 1
PORTB.1 = 0
PAUSEUS 139
PORTB.0 = 0
PAUSEUS 270
vertpulse = vertpulse + 1
IF vertpulse < 512
THEN GOTO horizloop
ELSE GOTO buttonloop
horizloop:
PORTB.2 = 0
PORTB.3 = 1
PAUSEUS 139
PORTB.3 = 0
PORTB.2 = 1
PAUSEUS 50
ADCIN 0, adval ' A/D 8 bit value from PORTA.0 into adval
SEROUT2 PORTC.6,16416,[BIN8 adval,13,10] ' Output 8 bit word serially to PC from C.6
PAUSE 87
horizpulse = horizpulse + 1
IF horizpulse < 784
THEN GOTO horizloop
ELSE GOTO vertloop
END

[mister_e]

1.) Is there a way to split PORTA into analog and digital inputs?

for sure... see datasheet in the A/D section.. ADCON1 TABLE 19-2

will be interesting to have kind of flowchart and schematic for the other problems you have.

[Darrel Taylor]

TurboLS,

What version of PBP are you using? I've never seen this work in any versions I've had.

IF vertpulse < 512
THEN GOTO horizloop
ELSE GOTO buttonloop

I've wanted to use that type of syntax before, but I get nothing but errors. Did I miss an update or something. I have 2.45

Darrel

[TurboLS]

I am using 2.46 and I will have a pic up soon that has the timing scheme. thanks for the replies.