Can't get OC1B (pin 10) to output

Question

I'm trying to get this program to use channel B for the output waveform using the phase correct PWM mode and using OCR1A as the top. With a 50% duty ratio I'm attempting to get a 10 Hz freq. I'm able to adjust the OC1A (Pin 9) if I set TCCR1A to 0x43; but nothing comes from pin 10. Code:

include "avr/io.h"
void setup() 
{ 
 DDRB = 0x6; //set pins 9 and 10 as output 
 /*set operation Toggle mode; WGM13:0 = 1011 phase correct PWM 
CS12:0 = 101 prescaler = 1024*/
 TCCR1A = 0x23; 
 TCCR1B = 0x15;
 OCR1A = 0x187; //391 for 50% duty cycle 
 TCNT1 = 0; //clear counter and update OCR1A 
} 
void loop() 
{ }

• Sim Son: It's much more readable to configure registers using bit operations like TCCR1A |= (1<<COM1A1);. Pin 10 refers to the arduino's pin 10?
• Kwasmich: Haven't looked into the spec but maybe you want to try setting OCR1AL = 0x87 and OCR1AH = 0x01 separately.

Answer 1

You are using Timer/Counter 1 in Fast PWM Mode with TOP set to OCR1A:
OCR1Aonly describes the number to what it counts up so, 0...391 in your case.
You have to define the duty cycle with OCR1B. 50% would be 195.