Class _ctb: 8-bit counter with two compare units and one dead-time generator

This class is used by:

• ATtiny25/45/85 : counter1

Relatives

• (COUNTER,prescaler): class _psb prescaler
• (COUNTER,compare0): class _ocb compare unit with waveform generator
• (COUNTER,compare1): class _ocb compare unit with waveform generator
• (COUNTER,dtg): class _dtga dead time generator

Interrupts

• (COUNTER,irq), (COUNTER,irq,overflow): triggered when the counter counts from "max" to 0 (after_max) in up_loop counting mode, or when it counts from 0 to 1 (after_bottom) in updown_loop counting mode.

Actions

hwa( configure, ... ): configure the counting unit

hwa( configure, counter0,
 
     //  How the counter is clocked
     //
     clock,       none                       // No clock, counter stopped
                | ioclk [/ 2**(0..14)]       // IOCLK divided by 1,2,4,..16384
 
   [ direction,   up_loop, ]                 // Default, no other choice
   [ bottom,      0,       ]                 // Default, no other choice
 
     //  The maximum value the counter reaches
     //
   [ top,         0xFF | 0x00FF | 255 | max  // Hardware fixed value 0xFF (default)
                | compare2, ]                // Value stored in compare2
 
     //  When the overflow flag is set
     //
   [ overflow,    after_bottom ]             // When the counter restarts from 0
);

Note

If a compare unit is used, its configuration must be done inside the same context as the counter so that HWA has all the necessary informations to choose the correct register settings.

hw( read, ... ): get the count

uint8_t n = hw( read, counter0 );

hw( write, ... ), hwa( write, ... ): set the count

hw( write, counter0, value );

hwa( write, counter0, value );

Internals

Hardware registers:

• ccr: control register
• count: count register
• ocr0: output-compare A register
• ocr1: output-compare B register
• ocr2: compare C register
• dtps: dead-time prescaler register
• dta: dead-time A register
• dtb: dead-time B register

Logical registers:

• com0
• com1
• cs
• ctc
• dtg0h
• dtg0l
• dtg1h
• dtg1l
• dtgs
• foc0
• foc1
• ie
• if
• ocie0
• ocie1
• ocif0
• ocif1
• pwm0
• pwm1