CY8C21345 PSoC Core
The PSoC core is a powerful engine that supports a rich feature
set. The core includes a CPU, memory, clocks, and configurable
GPIO.
The M8C CPU core is a powerful processor with speeds up to
24 MHz (up to 12 MHz for E-grade devices), providing four MIPS
(two MIPS for E-grade devices) 8-bit Harvard architecture
microprocessor. The CPU uses an interrupt controller to simplify
 the programming of real time embedded events.
Program execution is timed and protected using the included
Sleep Timer and Watch Dog Timer (WDT).
Memory encompasses 16 KB of flash (8 KB for CY8C21x45
devices) for program storage, 1 KB of SRAM (512 bytes for
CY8C21x45 devices) for data storage, and EEPROM emulation
using the flash. Program flash uses four protection levels on
blocks of 64 bytes, allowing customized software IP protection.
The PSoC device incorporates flexible internal clock generators,
including a 24-MHz internal main oscillator (IMO). For A-grade
devices the 24-MHz IMO can also be doubled to 48 MHz for use
by the digital system. A low-power 32-kHz internal low-speed
oscillator (ILO) is provided for the Sleep Timer and WDT. If
crystal accuracy is required, the 32.768 kHz external crystal
oscillator (ECO) is available for use as a RTC, and can
 optionally generate a crystal-accurate 24-MHz system clock using a PLL.
The clocks, together with programmable clock dividers (as a
system resource), provide the flexibility to integrate almost
any timing requirement into the PSoC device.
PSoC GPIOs provide connection to the CPU, digital, and analog
resources of the device. Each pin’s drive mode may be selected
from eight options, allowing great flexibility in external
interfacing. Each pin can also generate a system interrupt.