Datasheet

Trakker Antares 241X Hand-Held Terminal Service Manual nugget
4-6
PC Card Interface
The VG-230 supports a PC card interface compatible with the PCMCIA version 2.0
standard. Interfaces supported are:
• I/O cards
• Up to 64MB of memory
• Flash memory
• Execute in place (XIP)
The PC card is powered by VCCRF, which is filtered VCC supply. Reset is an open
collector signal generated from RESOUT* per the PCMCIA specification. The PC card
programming voltage (VPPA) is switched from PS+12V with signal VPPEMA. VPA is
also wire OR’d with VCCRF per the PCMCIA specification.
Beeper Driver
Control signals BEEP0 and BEEP1 are input into PAL (U101) that, in turn, control
BLOUD and BDRIVE. These signals produce a waveform across the beeper located on
the LCD flex cable. BEEP0 and BEEP1 are produced by the ASIC as a result of control
registers in the ASIC. Volumes produced are Off, Quiet, Normal, Loud, and Very Loud.
Sound frequency is controlled by the frequency at which BEEP0 and BEEP1 are
toggled.
ASIC
Terminal specific functionality is implemented in an ASIC. The general block diagram
of the ASIC is shown below. The ASIC implements all digital logic necessary to
implement terminal functionality. A second 8250-compatible UART is implemented to
interface to intelligent input devices and to provide a factory test and debug interface for
software development. The count gathering logic includes buffer counters, a terminal
count interrupt, a DMA transfer on overflow, and initiate count gathering on a
configurable white-to-black or black-to-white transition. The Beep control logic allows
beep duration to be set in hardware. An interrupt sharing multiplexer is provided that
routes multiple interrupts to a single input of the 8259 interrupt controller.