GE Vivid S5 N, Service Manual

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GE
P
ART
N
UMBER
FN091065, R
EVISION
2 VS5 N
AND
VS6 N
S
ERVICE
M
ANUAL
5-10 Section 5-3 - Front End Unit
P R E L I M I N A R Y
5-3-3 RFI_AM Board
The RFI_AM Board combines the following functionalities:
• Front End Control
• Radio Frequency & Tissue Processing
• PCI Bus Interface
5-3-3-1 Tasks Performed by the RFI_AM Board
• System Master Clock generator
• Transmitter Control
• ATGC Control
• Receive Focusing Control
• Analog Test Signal Generator
• Tx voltage Enable/Disable
• Probe Sensing
• Control of TR32, PIB or PSB Boards
• Ultrasound data acquisition and processing
Figure 5-8 RFI_AM Block Diagram
5-3-3-2 Watchdog and Power ON Reset
For safety reasons, a HW watchdog stops ultrasound transmit and resets the DSP if the DSP stops
toggling the watchdog inputs.
Once enabled, it is not possible to disable the watchdog unless the board is reset, or power is cycled.
5-3-3-3 Boot-up of DSP and Firmware
When the power is turned ON, the DSP is reset, and all FPGAs are blank. The DSP is connected to PCI
directly, and can only boot up with help from the Host.