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enCoRe™ V CY7C643xx, enCoRe™ V LV CY7C604xx TRM, Document No. 001-32519 Rev *H
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Flash bank
A group of flash ROM blocks where flash block numbers always begin with ‘0’ in an individual
flash bank. A flash bank also has its own block level protection information.
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.
flip-flop
A device having two stable states and two input terminals (or types of input signals) each of
which corresponds with one of the two states. The circuit remains in either state until it is made
to change to the other state by application of the corresponding signal.
frequency
The number of cycles or events per unit of time, for a periodic function.
G
gain
The ratio of output current, voltage, or power to input current, voltage, or power, respectively.
Gain is usually expressed in dB.
ground
1. The electrical neutral line having the same potential as the surrounding earth.
2. The negative side of DC power supply.
3. The reference point for an electrical system.
4. The conducting paths between an electric circuit or equipment and the earth, or some con-
ducting body serving in place of the earth.
H
hardware
A comprehensive term for all of the physical parts of a computer or embedded system, as distin-
guished from the data it contains or operates on, and the software that provides instructions for
the hardware to accomplish tasks.
hardware reset
A reset that is caused by a circuit, such as a POR, watchdog reset, or external reset. A hardware
reset restores the state of the device as it was when it was first powered up. Therefore, all regis-
ters are set to the POR value as indicated in register tables throughout this manual.
hexadecimal
A base 16 numeral system (often abbreviated and called hex), usually written using the symbols
0-9 and A-F. It is a useful system in computers because there is an easy mapping from four bits
to a single hex digit. Thus, one can represent every byte as two consecutive hexadecimal digits.
Compare the binary, hex, and decimal representations:
bin
= hex
= dec
0000b = 0x0
= 0
0001b = 0x1
= 1
0010b = 0x2
= 2
...
1001b = 0x9
= 9
1010b = 0xA
= 10
1011b = 0xB
= 11
...
1111b = 0xF
= 15
So the decimal numeral 79 whose binary representation is 0100 1111b can be written as 4Fh in
hexadecimal (0x4F).
high time
The amount of time the signal has a value of ‘1’ in one period, for a periodic digital signal.