CY8C20224_12 Datasheet, PDF (36/41 Pages) Cypress Semiconductor – CapSense® PSoC® Programmable System-on-Chip™

CY8C20224, CY8C20324
CY8C20424, CY8C20524
Glossary (continued)
emulator
Duplicates (provides an emulation of) the functions of one system with a different system, so that
the second system appears to behave like the first system.
External Reset An active high signal that is driven into the PSoC device. It causes all operation of the CPU and
(XRES)
blocks to stop and return to a pre-defined state.
Flash
An electrically programmable and erasable, non-volatile technology that provides you the
programmability and data storage of EPROMs, plus in-system erasability. Non-volatile means
that the data is retained when power is OFF.
Flash block
The smallest amount of Flash ROM space that may be programmed at one time and the smallest
amount of Flash space that may be protected. A Flash block holds 64 bytes.
frequency
The number of cycles or events per unit of time, for a periodic function.
gain
The ratio of output current, voltage, or power to input current, voltage, or power, respectively.
Gain is usually expressed in dB.
I²C
A two-wire serial computer bus by Philips Semiconductors (now NXP Semiconductors). I2C is an
Inter-Integrated Circuit. It is used to connect low-speed peripherals in an embedded system. The
original system was created in the early 1980s as a battery control interface, but it was later used
as a simple internal bus system for building control electronics. I2C uses only two bi-directional
pins, clock and data, both running at +5V and pulled high with resistors. The bus operates at 100
kbits/second in standard mode and 400 kbits/second in fast mode.
ICE
The in-circuit emulator that allows you to test the project in a hardware environment, while
viewing the debugging device activity in a software environment (PSoC Designer).
input/output (I/O) A device that introduces data into or extracts data from a system.
interrupt
A suspension of a process, such as the execution of a computer program, caused by an event
external to that process, and performed in such a way that the process can be resumed.
interrupt service
routine (ISR)
A block of code that normal code execution is diverted to when the M8C receives a hardware
interrupt. Many interrupt sources may each exist with its own priority and individual ISR code
block. Each ISR code block ends with the RETI instruction, returning the device to the point in
the program where it left normal program execution.
jitter
1. A misplacement of the timing of a transition from its ideal position. A typical form of corruption that occurs on
serial data streams.
2. The abrupt and unwanted variations of one or more signal characteristics, such as the interval between
successive pulses, the amplitude of successive cycles, or the frequency or phase of successive cycles.
low-voltage detect A circuit that senses V_DD and provides an interrupt to the system when V_DD falls lower than a selected threshold.
(LVD)
M8C
An 8-bit Harvard-architecture microprocessor. The microprocessor coordinates all activity inside
a PSoC by interfacing to the Flash, SRAM, and register space.
master device
A device that controls the timing for data exchanges between two devices. Or when devices are
cascaded in width, the master device is the one that controls the timing for data exchanges
between the cascaded devices and an external interface. The controlled device is called the
slave device.
Document Number: 001-41947 Rev. *L
Page 36 of 41