17.14.4 Timer/Counter 0 Low and High byte
The TCNT0L and TCNT0H register pair represents the 16-bit value, TCNT0.The low byte [7:0] (suffix L) is accessible at the original offset. The high byte [15:8] (suffix H) can be accessed at offset + 0x01. For more details on reading and writing 16-bit registers, refer to Accessing 16-bit Registers.
| Name: | TCNT0L and TCNT0H |
| Offset: | 0x28 |
| Reset: | 0x00 |
| Property: | - |
| Bit | 15 | 14 | 13 | 12 | 11 | 10 | 9 | 8 | |
| TCNT0[15:8] | |||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
| Bit | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | |
| TCNT0[7:0] | |||||||||
| Access | R/W | R/W | R/W | R/W | R/W | R/W | R/W | R/W | |
| Reset | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | |
Bits 15:0 – TCNT0[15:0] Timer/Counter 0
TCNT0H and TCNT0L are combined into TCNT0.
Modifying the counter (TCNT0) while the counter is running introduces a risk of missing a compare match between TCNT0 and one of the OCR0x Registers.
Writing to the TCNT0 Register blocks (removes) the compare match on the following timer clock for all compare units.