Citizen CLP-621, Техническое руководство

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2-2. Operation of Control Parts
2-19
CLP-621 & CLP-631
(a) CPU
The CPU is a microprocessor with 32-bit architecture. The clock fed to the CPU is 16 MHz.
The CPU internally multiplies this 16 MHz by 8 times and uses 128 MHz clock. The CPU
includes cache memory, RAMs, DMA controller, serial I/F, USB function controller, A/D
converter, etc.
(b) Flash ROM
A flash ROM of 16M bits (2M bytes) that stores the firmware and CG (character generator)
(c) SDRAM (Synchronous dynamic RAM)
A SDRAM of 64M bits (8M bytes) that is used as working area, input buffer and download
buffer
(d) Custom IC
The custom IC incorporates a control circuit for the interface I/O port, motors, print head,
etc.
(e) Head control
This is a circuit to control the thermal head driver incorporated in the thermal head. It also
checks if a thermal element of the thermal head is faulty.
(f) PF motor driver
This is a circuit to drive the PF Motor. The PF Motor is a stepping motor.
(g) Ribbon motor driver
This is a circuit to drive the Ribbon Motor F and Ribbon Motor R. These motors are
stepping motors. The rotational direction of the Ribbon Motor R is changed by the setting
of the Ribbon Winding Selection Switch.
(
h
) Buzzer
The buzzer is driven when an alarm, etc. occurs.
(i) Fan
Cooling fan for the ribbon motor. When the temperature of the Ribbon Motor F (take-up
side motor) exceeds a certain value, this fan starts to work.