Cpu; Flash Rom; Sdram (Synchronous Dynamic Ram); Fpga - Citizen CL-E720DT Technical Manual

(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.
2-15
Chapter 2 Operating Principles
2-2.
Operation of Control Parts
CL-E720DT