To challenge this, I wrote a couple of programs
(1) PWM generator for CY8CKIT-044 (CY8C4247AZI-M485)
Read compare value (0~999) from UART and generate 1kHz PWM with the compare value as duty.
(2) PWM measure for CY8CKIT-042 (CY8C4245AXI-483)
Sample PWM pulse with 10kHz clock and show the count/duty on UART
as well as when count is less than 1000 (10%?) light LED_B (Pin_1)
if count is greater than 9000 (90%?) light LED_R (Pin_2)
After connecting two boards using GND and D3 pin (PWM_OUT and PWM_IN) I started (1) then (2).
(1) starts with 500/1000 (~= 50%) then I entered 100, 950, 500, 100, each a few seconds appart
The pwm measure (2) reported
Since both boards are running asynchronously, the values are not exact, but IMHO reasonably close.
Thanks for offering some help, very much appreciated.
Eventually I found my problem after sleeping over it. Turns out I had had a wrong counter setting and I had to include a Sync Element to sort out some random glitches. Now all good working great,