Cypress manual CYV15G0404RB HOTLink II Operation, CYV15G0404RB Receive Data Path

CYV15G0404RB

Pin Definitions (continued)

CYV15G0404RB Quad HOTLink II Deserializing Reclocker

Name	IO Characteristics	Signal Description
TDO	3-State LVTTL Output	Test Data Out. JTAG data output buffer. High-Z while JTAG test mode is not
		selected.
TDI	LVTTL Input,	Test Data In. JTAG data input port.
	internal pull up
	LVTTL Input,	JTAG reset signal. When asserted (LOW), this input asynchronously resets the
TRST
	internal pull up	JTAG test access port controller.
Power
VCC		+3.3V Power.
GND		Signal and Power Ground for all internal circuits.

CYV15G0404RB HOTLink II Operation

The CYV15G0404RB is a highly configurable, independent clocking, quad-channel reclocking deserializer that supports reliable transfer of large quantities of digital video data, using high-speed serial links from multiple sources to multiple desti- nations. This device supports four 10-bit channels.

CYV15G0404RB Receive Data Path

Serial Line Receivers

Two differential Line Receivers, INx1± and INx2±, are available on each channel to accept serial data streams. The associated INSELx input selects the active Serial Line Receiver on a channel. The Serial Line Receiver inputs are differential, and can accommodate wire interconnect and filtering losses or transmission line attenuation greater than 16 dB. For normal operation, these inputs must receive a signal of at least VIDIFF > 100 mV, or 200 mV peak-to-peak differential. Each Line Receiver can be DC or AC coupled to +3.3V powered fiber-optic interface modules (any ECL/PECL family, not limited to 100K PECL) or AC coupled to +5V powered optical modules. The common mode tolerance of these line receivers accommodates a wide range of signal termination voltages. Each receiver provides internal DC restoration, to the center of the receiver’s common mode range, for AC coupled signals.

Signal Detect/Link Fault

Each selected Line Receiver (that is, that routed to the clock and data recovery PLL) is simultaneously monitored for

•Analog amplitude above amplitude level selected by SDASELx

•Transition density above the specified limit

All of these conditions must be valid for the Signal Detect block to indicate a valid signal is present. This status is presented on the LFIx (Link Fault Indicator) output associated with each receive channel, which changes synchronous to the receive interface clock.

Analog Amplitude

While most signal monitors are based on fixed constants, the analog amplitude level detection is adjustable to allow operation with highly attenuated signals, or in high noise environments. The SDASELx latch sets the analog amplitude level detection via the device configuration interface. The SDASELx latch sets the trip point for the detection of a valid signal at one of three levels, as listed in Table 1. This control input affects the analog monitors for all receive channels. The Analog Signal Detect monitors are active for the Line Receiver, as selected by the associated INSELx input.

Table 1. Analog Amplitude Detect Valid Signal Levels[5]

SDASEL Typical Signal with Peak Amplitudes Above

00Analog Signal Detector is disabled

01140 mV p-p differential

10280 mV p-p differential

11420 mV p-p differential

Transition Density

The Transition Detection logic checks for the absence of transitions spanning greater than six transmission characters (60 bits). If there are no transitions in the data received, the Detection logic for that channel asserts LFIx.

Range Controls

•Range controls reporting the received data stream inside normal frequency range (±1500 ppm[21])

•Receive channel enabled

•Reference clock present

•ULCx not asserted.

Note

The CDR circuit includes logic to monitor the frequency of the PLL Voltage Controlled Oscillator (VCO) samples the incoming data stream. This logic ensures that the VCO

5.The peak amplitudes listed in this table are for typical waveforms that generally have 3–4 transitions for every ten bits. In a worst case environment the signals may have a sine-wave appearance (highest transition density with repeating 0101...). Signal peak amplitudes levels within this environment type could increase the values in the table above by approximately 100 mV.

Document #: 38-02102 Rev. *C Page 11 of 27

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