Hey, Andrew... nice job.
BigDumbDinosaur wrote:
BitWise wrote:
I tried out Mike's idea of using a PIC16F18313 to create clock signals for a 65(C)02 and 65(C)51 plus a DS1813 like EconoReset pulse.
The code, schematics and resulting waveforms can be found here
https://github.com/andrew-jacobs/hz-maker.
More testing is required but looks promising.
Are you planning to produce these?
Hi BigD.
I have a programmer and could perhaps help out state-side users.
I should mention that this is an updated version of the 8-pin ClockGen circuit I posted a couple years ago. That version had a lower frequency Clock and an NCO (Numerically Controlled Oscillator) with only a 16-bit phase increment register which limited NCO output to about 307200-Hz (19200x16). The new PIC 18000 series devices support a higher speed clock and have 20-bit NCO phase accumulator and phase increment registers. Some possible settings for ACIA clock include;
Code:
--- nco output ------- ncoinc tolerance
500000x16 (8000000-Hz) 524288 ±0.00000%
460800x16 (7372800-Hz) 483184 ±0.00004%
230400x16 (3686400-Hz) 241592 ±0.00004%
115200x16 (1843200-Hz) 120796 ±0.00004%
57600x16 ( 921600-Hz) 60398 ±0.00004%
38400x16 ( 614400-Hz) 40265 ±0.00079%
19200x16 ( 307200-Hz) 20133 ±0.00169%
9600x16 ( 153600-Hz) 10066 ±0.00327%
4800x16 ( 76800-Hz) 5033 ±0.00327%
2400x16 ( 38400-Hz) 2517 ±0.01659%
A 14-pin version can include jumpers to set the CPU clock (1/2/4/8-MHz) and the ACIA clock. Having a jumper to select ACIA clock frequency might be handy if using a 68B50 or HD63B50.
Cheerful regards, Mike