Citizen CL-E720DT, Technical Manual

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Chapter 2 Operating Principles
2-2.
Operation of Control Parts
2-15
CL-E720DT
(1)
CPU
The CPU is a microprocessor with 32-bit architecture. The clock fed to the CPU is 48 MHz.
The CPU internally multiplies this 48 MHz by 8 times and uses 384 MHz clock. The CPU
includes cache memory, RAMs, DMA controller, serial I/F, USB function controller, LAN
function controller, A/D converter, etc.
(2)
Flash ROM
A flash ROM of 128M bits (16M bytes) that stores the firmware and CG (character generator).
(3) SDRAM (Synchronous dynamic RAM)
A SDRAM of 256M bits (32M bytes) that is used as working area, input buffer and download
buffer
(4) FPGA
The FPGA (Field-Programmable Gate Array) incorporates a control circuit for the interface I/O
port, motors, print head, etc.
(5) Head c
o
ntrol
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.
(6) Stepping motor driver (For “SA PF Motor”)
This is a circuit to drive the “SA PF Motor”. The “SA PF Motor” is a stepping motor.
(7)
Buzzer
The buzzer is driven when an alarm, etc. occurs.