Timing Mathematics¶
Mathematical Description of Carrier and Packet Timing
Overview¶
REVA operates using two independent timing layers:
- Carrier Timing
- Packet Timing
The carrier defines pulse repetition rate.
The packet system defines how those pulses are organized into bursts and envelopes.
Carrier Frequency¶
The carrier frequency is generated by Timer1.
For a carrier frequency (f_c), the carrier period is:
$$ T_c = \frac{1}{f_c} $$
Example: 90 kHz¶
$$ T_c = \frac{1}{90000} $$
$$ T_c = 11.11\ \mu s $$
Example: 120 kHz¶
$$ T_c = \frac{1}{120000} $$
$$ T_c = 8.33\ \mu s $$
Timer1 Frequency Equation¶
$$ f_c = \frac{F_{CPU}}{2N(1+OCR1A)} $$
Where:
| Symbol | Meaning |
|---|---|
| (F_{CPU}) | CPU clock frequency |
| (N) | Prescaler |
| (OCR1A) | Compare register |
For REVA:
$$ F_{CPU} = 16\,MHz $$
Packet Structure¶
Packet
├─ Segment 1
├─ Segment 2
├─ Segment 3
└─ ...
Each segment contains:
Pulse Count
Gap Time
Segment Duration¶
If a segment contains (N) carrier cycles:
$$ T_{pulse} = N \cdot T_c $$
The total segment duration becomes:
$$ T_{segment} = T_{pulse} + T_{gap} $$
Packet Duration¶
$$ T_{packet} = \sum T_{segment} + T_{final} $$
Packet Frequency¶
$$ f_{packet} = \frac{1}{T_{packet}} $$
Packet Density¶
$$ Density = \frac{T_{active}}{T_{packet}} $$
Pulse Scaling¶
$$ N' = k_p \cdot N $$
Gap Scaling¶
$$ T'{gap} = k_g \cdot T{gap} $$
Geometry Preservation¶
Scaling changes size but preserves structure.
Original Geometry
↓
Scaling
↓
Larger Geometry