Universum FT-81031, Руководство по обслуживанию

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EPROM (M27W401)
The M27W401 is a low voltage 4Mbit EPROM (UV erasable). It is ideally suited for micro processor systems requiring
large data or program storage and is organised as 522,288 by 8 bits. The M27W401 operates in the read mode with a
supply voltage as low as 2.7V at –40 to 85°C temperature range.
Features:
n Organisation 512K x 8
n Single 3.3V power supply
n Operationally Compatible with Existing Megabit EPROMs
n Industry Standard 32-pinDual-in-line Package
n All inputs/Outputs Fully TTL Compatible
n 8-Bit Output for Use in Microprocessor-Based Systems
n Power Saving CMOS Technology
n 3-State Output Buffers
n 400 mV Minimum DC Noise Immunity with Standard TTL Loads
n Latch up immunity of 250mA on all input and output pins
n No pull-up resistors required
n Low power dissipation
100Hz FEATURE BOX
VPC3215, CIP3250, SDA9400, DDP3310
The feature box consists of four I²C controlled ICs:
Video Processor VPC3215
Component Interface Processor CIP3250
Digital Image Processor SDA9400
Digital Deflection Processor DDP3310
The input supplies to the feature box are +12V, +5V. The ICs do also need a supply of 3.3V, which is regulated
by IC4 LM314.
Besides the composite video in normal operation and luma/chroma inputs in the SVHS applications, there are also
R-G-B-FB inputs from the PIP module.
OSD R-G-B-FB inputs from the Megatext IC or from the controller in the case of TV-text option. While the 50Hz sync
signals for PIP are supplied by the VPC3215, the 100Hz sync signals for OSD are supplied by the DDP3310.
Control signals for HV stage such as VertQ, Vert, HDrive, EW (East-West) and SVM (Scan Velocity Modulation) are
produced by this module. VProt and HProt input signals are used for protection. There are also a flyback sample
signal from HV stage and the sense signal from the CRT board.
The feature box also supports the VGA mode.
VPC32X5 (Video Processor)
Figure 1
As seen in figure 1 all the processings in VPC are digital. This IC has four composite, one SVHS input, and one
composite output which is used for teletext. In AK28 the main video input is Vin2, which is also used for luma input in
SVHS applications.
After switching the inputs the signals are converted to digital via two 8 bit ADCs. And these digital data are processed
to produce the 4:2:2 formatted digital YUV signals. The main features are, multi-standard color decoding including all
sub-standards, multi-standard sync processing, adaptive 4H comb filter, linear horizontal scaling, as well as nonlinear
horizontal scaling (panorama vision.) It provides 50Hz vertical and 15625Hz horizontal sync signals for the PIP module.