J5
J5 exposes some 6×09 signals that do not appear on The M8 Bus
| J5 Pin | Signal |
|---|---|
| 1 | 6×09 Bus Status (BS) |
| 2 | NVBAT |
| 3 | 6×09 /FIRQ “Fast” Interrupt Request |
| 4 | 6×09 /RESET Reset Interrupt Request |
| 5 | M8 Bus Select 1 (BSEL1) |
| 6 | Ground |
The NVBAT pin on J5 has two possible uses.
It is connected directly to the on board battery.
So it can either be used to replace the on board with an external battery, or can convey backup power to additional circuits such as, for example, an RTC.
Return to SST-6809