IDT
PES24N3A User Manual
2
April 10, 2008
Notes
To define the active polarity of a signal, a suffix will be used. Signals ending with an ‘N’ should be inter-
preted as being active, or asserted, when at a logic zero (low) level. All other signals (including clocks,
buses and select lines) will be interpreted as being active, or asserted when at a logic one (high) level.
To define buses, the most significant bit (MSB) will be on the left and least significant bit (LSB) will be on
the right. No leading zeros will be included.
Throughout this manual, when describing signal transitions, the following terminology is used. Rising
edge indicates a low-to-high (0 to 1) transition. Falling edge indicates a high-to-low (1 to 0) transition. These
terms are illustrated in Figure 1.
Figure 1 Signal Transitions
Numeric Representations
To represent numerical values, either decimal, binary, or hexadecimal formats will be used. The binary
format is as follows: 0bDDD, where “D” represents either 0 or 1; the hexadecimal format is as follows:
0xDD, where “D” represents the hexadecimal digit(s); otherwise, it is decimal.
The compressed notation ABC[x|y|z]D refers to ABCxD, ABCyD, and ABCzD.
The compressed notation ABC[x:y]D refers to ABCxD, ABC(x+1)D, ABC(x+2)D,... ABCyD if x < y or to
ABCxD, ABC(x-1)D, ABC(x-2)D,... ABCyD if x > y.
Data Units
The following data unit terminology is used in this document.
In quadwords, bit 63 is always the most significant bit and bit 0 is the least significant bit. In double-
words, bit 31 is always the most significant bit and bit 0 is the least significant bit. In words, bit 15 is always
the most significant bit and bit 0 is the least significant bit. In bytes, bit 7 is always the most significant bit
and bit 0 is the least significant bit.
Term
Words
Bytes
Bits
Byte
1/2
1
8
Word
1
2
16
Doubleword (Dword)
2
4
32
Quadword (Qword)
4
8
64
Table 1 Data Unit Terminology
1
2
3
4
high-to-low
transition
low-to-high
transition
single clock cycle
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Страница 14: ...IDT List of Figures PES24N3A User Manual viii April 10 2008 Notes...
Страница 18: ...IDT Register List PES24N3A User Manual xii April 10 2008 Notes...
Страница 38: ...IDT Clocking Reset and Initialization Clock Operation PES24N3A User Manual 2 10 April 10 2008 Notes...
Страница 64: ...IDT Link Operation PES24N3A User Manual 4 8 April 10 2008 Notes...
Страница 88: ...IDT Power Management PES24N3A User Manual 7 4 April 10 2008 Notes...
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