Lexicon 960L - Meter Bridge Module

Lexicon
7-53
9004 0004 GPDR GPIO pin direction register
9004 0008 GPSR GPIO pin output set register
9004 000C GPCR GPIO pin output clear register
9004 0010 GRER GPIO rising-edge register
9004 0014 GFER GPIO falling-edge register
9004 0018 GEDR GPIO edge detect status register
9004 001C GAFR GPIO alternate function register
9005 0000 ICIP Interrupt controller IRQ pending
9005 0004 ICMR Interrupt controller mask register
9005 0008 ICLR Interrupt controller level register
9005 000C ICCR Interrupt controller control register
9005 0010 ICFP Interrupt controller FIQ pending
9005 0020 ICPR Interrupt controller pending register
Meter Bridge Module
The meter bridge circuitry is represented on schematic 060-13389. The module connects to the main board
via J4 (main board sheet 7). The meter bridge consists of 24 LEDs in a three row by eight column matrix.
The LEDs are divided into two groups, each controlled by an 8 bit register (U1, U2, sheet 1). Software
writes a sequence of bit patterns to activate the groups one at a time turning on the LEDs in that group.
RED
GREEN
GREEN
RED
GREEN
GREEN
RED
GREEN
GREEN
RED
GREEN
GREEN
RED
GREEN
GREEN
RED
GREEN
GREEN
RED
GREEN
GREEN
RED
GREEN
GREEN
Group B1 Group B2 Group B3 Group B4 Group A1 Group A2 Group A4Group A3
TOP
MID
BOT
Figure 7-1 Meter Bridge