The Printer's engine electronics (Main PCA) is controlled by a
Kayak ASIC. Kayak is the application-specific integrated circuit
(ASIC), designed in Hewlett-Packard's Vancouver Printer Division,
forming the heart of the thermal-inkjet large format printer digital
electronics.
Hardware Description
The Kayak ASIC is fed with a 15.975MHz crystal-quartz which through
a phase lock loop (PLL) is raised to 192MHz and after that divided
to the ColdFire frequency of 96MHz and further divided to the external
memory bus of 48MHz.
The Kayak ASIC incorporates the CF3_g Motorola CF3MRSX processor
mega cell. As implemented in Kayak, the processor, with 8KB of unified
cache, has a maximum operating frequency of 98MHz and at this frequency
it is capable of approx. 70 MIPS.
Two physical EIO slots are supported from which the optional formatters
and EIO cards will be plugged. Three expansion options are currently
supported.
The Main PCA will come with an on-board 2MB(x16) flash memory
that will allow both the end user and service engineers to upgrade
with the latest firmware code available.
A total of 16MB SDRAM (x32) or 32MB SDRAM (depending on the Printer
Model) will be loaded in the engine PCA, not allowing further user
self-memory upgrades.
The memory bus is also used to control Navata gate array. Navata
is a customized ASIC to control most of the Printer's sensors (ISS
optical sensors, pinch wheels, digital encoder, etc.), Power Supply,
Scan-Axis Motor driver, Vacuum Fan, Front Panel, Carriage, etc.
A 16k serial EEPROM is used to store different line calibration
parameters and the Printer's life history (number of plots, etc.).
The ISS PCA also contains an EEROM that contains a backup of all
critical parameters from the Main EEROM.
The Main PCA has an analogue IC which controls two DC motors (IDS
and paper) and one stepper motor (Service Station). This IC, as
well as the IC in the Carriage PCA, is controlled through the VPR
serial interface from the Kayak ASIC at a bus clock frequency of
1.6MHz.
From the Main PCA the Interconnect Cable connects to the Interconnect
PCA (located on the right hand side of the Printer) which then splits
into different subsystems: Front Panel, IDS PCA, Aerosol Fan, Service
Station and media loading sensors (pinch, media sensor and media
button).
Two discrete drivers are implemented for the Carriage Motor driver
and the Vacuum Fan.
The Main PCA comes with fully protected motor drivers for Carriage,
Paper-Axis, Service Station and IDS motors. Any short-circuit will
be detected and protected.
Trailing Cables come with an interlock loop that will prevent
from turning on voltages in the Carriage while the Trailing Cable
is not properly connected. A similar approach of using an interlock
pair is used in the Interconnect Cable to ensure it is properly
connected.
The EIO slots do not allow for hot insertions while the machine
is powered. That is why it is very important to always power-off
the Printer before inserting the EIO Card or the Formatter or else
the Main PCA could be burned.
Serial channel, to be used for line production and service purposes
only, will be isolated from Kayak pins with a GPIO in the Navata
ASIC.
