PRELIMINARY
CYP15G0403DXB
CYV15G0403DXB
Document #: 38-02065 Rev. *C
Page 7 of 43
Pin Definitions
CYP(V)15G0403DXB Quad HOTLink II Transceiver
Name
I/O Characteristics
Signal Description
Transmit Path Data and Status Signals
TXDA[7:0]
TXDB[7:0]
TXDC[7:0]
TXDD[7:0]
LVTTL Input,
synchronous,
sampled by the
associated
TXCLKx or
REFCLKx [2]
Transmit Data Inputs. TXDx[7:0] data inputs are captured on the rising edge of
the transmit interface clock. The transmit interface clock is selected by the
TXCKSELx latch via the device configuration interface, and passed to the encoder
or Transmit Shifter. When the Encoder is enabled, TXDx[7:0] specifies the specific
data or command character sent.
TXCTA[1:0]
TXCTB[1:0]
TXCTC[1:0]
TXCTD[1:0]
LVTTL Input,
synchronous,
sampled by the
associated
TXCLKx or
REFCLKx [2]
Transmit Control. TXCTx[1:0] inputs are captured on the rising edge of the
transmit interface clock. The transmit interface clock is selected by the TXCKSELx
latch via the device configuration interface, and passed to the Encoder or Transmit
Shifter. The TXCTA[1:0] inputs identify how the associated TXDx[7:0] characters
are interpreted. When the Encoder is bypassed, these inputs are interpreted as
data bits. When the Encoder is enabled, these inputs determine if the TXDx[7:0]
character is encoded as Data, a Special Character code, or replaced with other
Special Character codes. See Table3 for details.
TXERRA
TXERRB
TXERRC
TXERRD
LVTTL Output,
synchronous to
REFCLKx [3],
synchronous to
RXCLKx when
selected as
REFCLKx,
asynchronous to
transmit channel
enable / disable,
asynchronous to loss
or return of
REFCLKx
±
Transmit Path Error. TXERRx is asserted HIGH to indicate detection of a transmit
Phase-Align Buffer underflow or overflow. If an underflow or overflow condition is
detected, TXERRx, for the channel in error, is asserted HIGH and remains
asserted until either a Word Sync Sequence is transmitted on that channel, or the
transmit Phase-Align Buffer is re-centered with the PABRSTx latch via the device
configuration interface. When TXBISTx = 0, the BIST progress is presented on the
associated TXERRx output. The TXERRx signal pulses HIGH for one transmit-
character clock period to indicate a pass through the BIST sequence once every
511 or 527 (depending on RXCKSELx) character times. If RXCKSELx = 1, a one
character pulse occurs every 527 character times. If RXCKSELx = 0, a one
character pulse occurs every 511 character times.
TXERRx is also asserted HIGH, when any of the following conditions is true:
• The TXPLL for the associated channel is powered down. This occurs when
OE2x and OE1x for a given channel are both disabled by setting OE2x = 0 and
OE1x = 0.
• The absence of the REFCLKx± signal
Transmit Path Clock Signals
REFCLKA
±
REFCLKB
±
REFCLKC
±
REFCLKD
±
Differential LVPECL
or single-ended
LVTTL input clock
Reference Clock. REFCLKx
± clock inputs are used as the timing references for
the transmit and receive PLLs. These input clocks may also be selected to clock
the transmit and receive parallel interfaces. When driven by a single-ended
LVCMOS or LVTTL clock source, connect the clock source to either the true or
complement REFCLKx input, and leave the alternate REFCLKx input open
(floating). When driven by an LVPECL clock source, the clock must be a differential
clock, using both inputs.
TXCLKA
TXCLKB
TXCLKC
TXCLKD
LVTTL Clock Input,
internal pull-down
Transmit Path Input Clock. When configuration latch TXCKSELx = 0, the
associated TXCLKx input is selected as the character-rate input clock for the
TXDx[7:0] and TXCTx[1:0] inputs. In this mode, the TXCLKx input must be
frequency-coherent to its associated TXCLKOx output clock, but may be offset in
phase by any amount. Once initialized, TXCLKx is allowed to drift in phase as
much as
±180 degrees. If the input phase of TXCLKx drifts beyond the handling
capacity of the Phase Align Buffer, TXERRx is asserted to indicate the loss of data,
and remains asserted until the Phase Align Buffer is initialized. The phase of the
TXCLKx input clock relative to its associated REFCLKx
± is initialized when the
configuration latch PABRSTx is written as 0. When the associated TXERRx is
deasserted, the Phase Align Buffer is initialized and input characters are correctly
captured.
Notes:
2.
When REFCLKx
± is configured for half-rate operation, these inputs are sampled relative to both the rising and falling edges of the associated REFCLKx±.
3.
When REFCLKx
± is configured for half-rate operation, these outputs are presented relative to both the rising and falling edges of the associated REFCLKx±.