Welch Allyn Duet CO2 Module - User Manual - Manual (Page 70)

Duet CO
2
Module OEM Implementation Manual
Page 70 Confidential Welch Allyn OEM Technologies
Operation
The following sequence loads the new executive code.
INITIALIZE SERIAL PORT
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LOAD THE BOOT LOADER
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CONVERT EXECUTIVE LOADER CODE TO BINARY
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LOAD BOOT AGENT
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LOAD REGISTER FILE IMAGE , IF SPECIFIED
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LOAD EXECUTIVE FILE
INITIALIZE THE SERIAL PORT
LOAD THE BOOT LOADER
If the –L1 switch is issued, the file specified by the –B switch is fetched from disk and loaded into
memory. If this file is not specified or does not exist, an error is issued and the program terminates.
CONVERT EXECUTIVE LOADER CODE TO BINARY
The file pointed to by the –M switch is pulled into memory and converted to binary. The module resets
into bootstrap mode by sending a continuous break signal to the module for a period of 750 msec. The
break signal is released and the module is given 250 msec to respond by transmitting a break signal
back to the PC. If the module responds within the 250-msec (What’s the edit?) period, the PC begins
the process of loading the boot agent. If this break signal is not received within the 250-msec (What’s
the edit?) period, the program issues an error and exits.
LOAD BOOT AGENT
In order for the module to determine the baud rate at which the agent is being loaded, the module looks
at the first char received.
If the –F switch is issued with a 0xf0, the boot agent is loaded at a maximum speed of 19200 baud. If
the –F switch is not issued; a single 0xFF is transmitted at 2400 baud to indicate the data is to be sent
at the respective baud rates.
Once the first char is transmitted, the boot agent must be immediately sent as a continuous serial
stream at the specified baud rate. Each char received by the module is subsequently echoed back to
the PC. If the char is sent and an echo is not registered within 100 msec, an error is assumed to have
occurred and the program issues an error and exits.
After the boot agent is loaded, the PC changes to 9600 baud and looks for a “
*
” char to indicate that the
boot agent is running on the module. The program waits a maximum of 100 msec to receive this char
and issues an error and exits if not received within this period.
LOAD REGISTER FILE IMAGE , IF SPECIFIED
The register file image is loaded into the module.