This can be found using the combination of the DS28E84 Security User Guide and datasheet. The sequence for a read and write memory are shown in Table 13 and Table 15 of the Security User Guide, while the 1-Wire time by time slot duration, 1-Wire Reset Cycle , and the Strong pullup delay. With this information we can calculate how long the write or read sequence by adding up the total time of each step of the read or write sequence.
For example if the DS28E84 is in Overdrive Speed mode, then from the datasheet:
- tRSTH = 48us
- tRSTL = 48us
- tSLOT = 16us
- tWM = 100ms
With the example write sequence below:
- 1W Reset: tRSTH +tRSTL = 96 us
- ROM select: tSLOT x 8 (Skip ROM) = 128us (Byte time)
- Length Byte: tSLOT x 8 = 128us
- Command: tSLOT x 8 = 128us
- Parameter: tSLOT x 8 = 128us
- New Page Date: tSLOT * 8 * 32 = 4096us
- CRC16: tSLOT * 16 = 256us
- Release Byte: tSLOT * 8 =128us
- Strong Pullup delay: tWM = 100ms
- Dummy Byte: tSLOT * 8 = 128us
- Length Byte: tSLOT * 8 = 128us
- Result Byte: tSLOT * 8 = 128us
- CRC16: tSLOT * 16 = 256us
The fastest write time in overdrive speed mode with the example sequence above would then be the total which is around 105.7ms.