Little Board/P5x Technical Manual
2–51
Utility Connectors (J16, J24)Seven functions appear on Utility 1, a 16-pin connector at J16. These are:
! Auxiliary power connections
! Power indicator LED
! PC speaker
! Push-button reset switch
! Keyboard interface
! External back-up battery
Table 2– 38 shows the pinout and signal definitions of the Utility Conne ctor. Sin ce the re are
connections for diverse features on this single connector, you would usually choose a discrete-wire
connector rather than a ribbon cable connector, though this is not a requiremen t. Table 2– 39 sho ws
manufacturer’s part numbers for both types of mating connectors.
Table 2– 38. Utility Connector (J16)
Pin Signal Name Function
1 -12V power Connect external -12V supply here for distribution to
expansion cards needing this voltage.
2 Ground Ground return
3 -5V power Connect external -5V supply here for distribution to
expansion cards needing this voltage.
4 Ground Ground return
5 LED Anode LED current source (+5V through 330 ohms)
6 RSVD No c onnection
7 Speaker + PC audio signal output
8 Ground Ground
9 Reset To one side of manual reset button.
10 N/C Reserved
11 Kbd Data Keyboard serial data
12 Kbd Clk Keyboard clock
13 Ground Keyboard ground
14 Kbd Power Keyboard +5V power
15 + Bat + Battery *
16 Ground - Battery *
* An external battery is not required.