Service manual

4. BOARD/UNIT DESCRIPTION
4.2 Service Manual BSM-4100
The MAIN board consists of system control block, display control block, recorder
control block and power control block.
The system control block has the host CPU which gets the operation key status,
displays the waveforms and numeric data and controls the recorder unit indirectly.
The program is stored in the 2 MB system ROM (flash EEPROM) for host CPU, 128
KB Boot ROM in the system control block, 1 MB system ROM (flash EEPROM)
for local CPU in the recorder control block.
When the instrument is turned on, the host CPU executes the program in the Boot
ROM. According to the program, the host CPU checks if the program card is
inserted into the slot on the MAIN board. When the host CPU recognizes that the
correct program card is inserted, the host CPU writes the program from the card to
each system ROM. This is called Boot. Therefore, this Boot system allows you to
upgrade the instrument without opening it. On the other hand, when the program
card is not inserted into the slot, the host CPU switches from the Boot ROM to the
system ROM in the system control block and executes the system program.
MAIN Board
Host CPU
Boot ROM
System ROM
Program card
<When the program card is inserted>
To the other ROMs
Host CPU
Boot ROM
System ROM
Program card
<When the program card is not inserted>
To the other ROMs
a) System control block
The system control block consists of the host CPU, Boot ROM, system ROM,
system RAM, backup RAM, real-time clock, two memory card interfaces, touch
screen controller, audio circuit and main gate array.
An MC68SEC000 is used as the host CPU. The clock frequency is 20 MHz. The
CPU controls the dedicated gate array, ASIC (Application Specific Integrated
Circuit) ACORN, which controls the hard keys, function dials, touch screen, alarm
indicator, QRS synchronous sound, alarm sound, real time clock, PCMCIA card
interface, DPU communication, RS-232C communication and QM-421P ATA card
interface.