CYP15G0101DXB Cypress Semiconductor Corporation., CYP15G0101DXB Datasheet - Page 13

• Manufacturer Part Number: CYP15G0101DXB
• Description: Single-channel Hotlink Ii Transceiver
• Manufacturer: Cypress Semiconductor Corporation.

Document #: 38-02031 Rev. *J
With the Encoder bypassed, the TXCT[1:0] inputs are
considered part of the data character and do not perform a
control function that would otherwise modify the interpretation
of the TXD[7:0] bits. The bit usage and mapping of these
control bits when the Encoder is bypassed is shown in Table 4.
In Encoder Bypass mode, the SCSEL input is ignored. All
clocking modes interpret the data in the same way.
Table 4. Encoder Bypass Mode (TXMODE[1:0 = LL)
Table 3. Transmit Operating Modes
TX Modes 1 and 2—Factory Test Modes
These modes enable specific factory test configurations. They
are not considered normal operating modes of the device.
Entry or configuration into these test modes will not damage
the device.
TX Mode 3—Atomic Word Sync and SCSEL Control of Special
Codes
When configured in TX Mode 3, the SCSEL input is captured
along with the TXCT[1:0] data control inputs. These bits
combine to control the interpretation of the TXD[7:0] bits and
the characters generated by them. These bits are interpreted
as listed in Table 5.
Note:
9.
TX Mode
0
1
2
3
4
5
6
7
8
TXD[0]
TXCT[1]
Signal Name
LSB is shifted out first.
TXCT[0]
TXD[1]
TXD[2]
TXD[3]
TXD[4]
TXD[5]
TXD[6]
TXD[7]
MM Atomic
MH Atomic
HM Interruptible
HH Interruptible
LM None
ML Atomic
LH None
HL Interruptible
LL
(LSB)
(MSB)
None
Word Sync
Sequence
[9]
Support
Bus Weight
None
None
None
Special
Character
Word Sync
None
Special
Character
Word Sync
None
Operating Mode
2
2
2
2
2
2
2
2
2
2
Control
SCSEL
0
1
2
3
4
5
6
7
8
9
Encoder Bypass
Reserved for test
Reserved for test
Encoder Control
Encoder Control
Encoder Control
Encoder Control
Encoder Control
Encoder Control
TXCT Function
10B Name
a
b
c
d
e
g
h
i
f
j
Table 5. TX Modes 3 and 6 Encoding
When TXCKSEL = MID or HIGH, the transmit channel
captures data into its Input Register using the TXCLK clock.
Word Sync Sequence
When TXCT[1:0] = 11, a 16-character sequence of K28.5
characters, known as a Word Sync Sequence, is generated on
the transmit channel. This sequence of K28.5 characters may
start with either a positive or negative disparity K28.5 (as
determined by the current running disparity and the 8B/10B
coding rules). The disparity of the second and third K28.5
characters in this sequence are reversed from what normal
8B/10B coding rules would generate. The remaining K28.5
characters in the sequence follow all 8B/10B coding rules. The
disparity of the generated K28.5 characters in this sequence
follow a pattern of either + + – – + – + – + – + – + – + – or
– – + + – + – + – + – + – + – +.
When TXMODE[1] = MID (open, TX modes 3, 4 and 5), the
generation of this character sequence is an atomic (non-inter-
ruptible) operation. Once it has been successfully started, it
cannot be stopped until all 16 characters have been
generated. The content of the Input Register is ignored for the
duration of this 16-character sequence. At the end of this
sequence, if the TXCT[1:0] = 11 condition is sampled again,
the sequence restarts and remains uninterrupted for the
following 15 character clocks.
If parity checking is enabled, the character used to start the
Word Sync Sequence must also have correct ODD parity. This
is true even though the contents of the TXD[7:0] bits do not
directly control the generation of characters during the Word
Sync Sequence. Once the sequence is started, parity is not
checked on the following 15 characters in the Word Sync
Sequence.
When TXMODE[1] = HIGH (TX modes 6, 7, and 8), the gener-
ation of the Word Sync Sequence becomes an interruptible
operation. In TX Mode 6, this sequence is started as soon as
the TXCT[1:0] = 11 condition is detected on the channel.
In order for the sequence to continue, the TXCT[1:0] inputs
must be sampled as 00 for the remaining 15 characters of the
sequence. If at any time a sample period exists where
TXCT[1:0] ≠ 00, the Word Sync Sequence is terminated, and
a character representing the data and control bits is generated
by the Encoder. This resets the Word Sync Sequence state
machine such that it will start at the beginning of the sequence
at the next occurrence of TXCT[1:0] = 11.
X
X
0
1
X
0
0
1
0 Encoded data character
1 K28.5 fill character
1 Special character code
1 16-character Word Sync Sequence
Characters Generated
CYW15G0101DXB
CYV15G0101DXB
CYP15G0101DXB
Page 13 of 39
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