CY7B923-400JI CYPRESS [Cypress Semiconductor], CY7B923-400JI Datasheet - Page 22

• Manufacturer Part Number: CY7B923-400JI
• Manufacturer: CYPRESS [Cypress Semiconductor]

Use of the Tables for Generating Transmission Characters
The appropriate entry in the table shall be found for the Valid
Data byte or the Special Character byte for which a Transmis-
sion Character is to be generated (encoded). The current val-
ue of the Transmitter’s running disparity shall be used to select
the Transmission Character from its corresponding column.
For each Transmission Character transmitted, a new value of
the running disparity shall be calculated. This new value shall
be used as the Transmitter’s current running disparity for the
next Valid Data byte or Special Character byte to be encoded
and transmitted. Table 1 shows naming notations and examples
of valid transmission characters.
Use of the Tables for Checking the Validity of Received
Transmission Characters
The column corresponding to the current value of the Receiv-
er’s running disparity shall be searched for the received Trans-
mission Character. If the received Transmission Character is
found in the proper column, then the Transmission Character
is valid and the associated Data byte or Special Character
code is determined (decoded). If the received Transmission
Character is not found in that column, then the Transmission
Character is invalid. This is called a code violation. Indepen-
dent of the Transmission Character’s validity, the received
Transmission Character shall be used to calculate a new value
of running disparity. The new value shall be used as the Re-
Table 2. Code Violations Resulting from Prior Errors
3. Otherwise, running disparity at the end of the sub-block is
Transmitted data character
Transmitted bit stream
Bit stream after error
Decoded data character
negative at the end of the 6-bit sub-block if the 6-bit
sub-block is 111000, and it is negative at the end of the 4-bit
sub-block if the 4-bit sub-block is 1100.
the same as at the beginning of the sub-block.
RD
101010 1001
101010 1011
Character
D21.1
D21.0
22
RD
+
+
ceiver’s current running disparity for the next received Trans-
mission Character.
Table 1. Valid Transmission Characters
Detection of a code violation does not necessarily show that
the Transmission Character in which the code violation was
detected is in error. Code violations may result from a prior
error that altered the running disparity of the bit stream which
did not result in a detectable error at the Transmission Char-
acter in which the error occurred. Table 2 shows an example of
this behavior.
Byte Name
010101 0101
010101 0101
D30.7
D31.7
Character
D0.0
D1.0
D2.0
D5.2
.
.
.
.
D10.2
D10.2
000
000
000
010
111
111
765
.
.
.
.
D
RD
IN
+
+
Data
or Q
00000
00001
00010
00010
11110
11111
43210
OUT
.
.
1
.
.
Code Violation
111010 1010
111010 1010
Character
D23.5
Hex Value
CY7B923
CY7B933
00
01
02
45
FE
FF
.
.
.
.
RD
+
+
+
+