FMC Link Controller

Authors:

Jonathan P. Newman

Version:

2

IO:

Frame Source, Register Access

ONIX ID:

23

ONIX Hubs:

PCIe Host

Description

The FMC Host Link Controller is used to control and monitor DS90UB9x-based serialized connections to hubs connected to a host such as headstages and miniscopes. It can control the voltage provided to those hubs and receives RF lock, CRC error, and other diagnostic information.

Note

Typical inplementaitons will default link voltages to 0. Often the link will need to be manually activated via the appropriate registers in order for a headstage to be used.

Warning

The maximum DC voltage that can be produced by this device may exceed the absolute maximum ratings for some headstages. Although they typically will have some form input overvoltage protection, the user should be careful to keep the voltage within a functional range.

Register Programming

Address	Name	Access	Time of Effect	POR Value	Reset Action	Description
0x00	ENABLE	R/W	On Reset	Implementation dependent, see hub documentation	None	The LSB is used to enable or disable the device data stream: 0x0: data output disabled 0x1: data output enabled
0x01	GPOSTATE	R/W	Immediate	0	0	GPO output state (bits 31 downto 3: ignore. bits 2 downto 0: ‘1’ = high, ‘0’ = low)
0x02	DESPWR	R/W	Immediate	1	None	Set link deserializer PDB state, 0 = deserializer power off else on. Does not affect port voltage.
0x03	PORTVOLTAGE	R/W	Immediate	EEPROM*	None	10 * link voltage. Valid values: 000 : Turn off 001 : 3.3 volts (min) … : 3.3 volts (min) 032 : 3.3 volts (min) 033 : 3.3 volts (min) 034 : 3.4 volts 035 : 3.5 volts … : … 108 : 10.8 volts 109 : 10.9 volts 110 : 11.0 volts (max) 111 : 11.0 volts (max) … : 11.0 volts (max)
0x04	SAVEVOLTAGE	W	Immediate	EEPROM*	None	Save link voltage to non-volatile EEPROM if greater than 0. This voltage will be applied after POR.
0x05	LINKSTATE	R	When LOCK or PASS change	0	None	Link state Bit 0: LOCK Bit 1: PASS
0x06	LINKOPTS	R/W	Inmmediate	0	None	Misc. options for the link device Bit 0: 0 Port auto-shutdown disabled 1 Port auto-shutdown enabled

Device To Host Data Frames

Each frame transmitted to the host is structured as follows:

This device produces frames when triggered by the CV, PP, or SL bits. These are defined as follows:

CV

Codeword valid. Indicates that the Status Codeword field has valid data. A frame is produced when this bit goes high. The codeword meaning is hub-dependent. See hub documentation for definitions.

PP

Parity check pass. This bit reflects the state of the PASS pin on the DS90UB9x4 deserializer.

• 0b0: One or more errors were detected in the received payload.

• 0b1: Error free transmission in forward channel operation.

A frame is produced whenever this bit changes state.

SL

SERDES lock. This bit reflects the state of the LOCK pin on the DS90UB9x4 deserializer, which monitors the lock status of FPD-Link III channel.

• 0b0: PLL is unlocked link is down.

• 0b1: PLL is locked, link is active.

A frame is produced whenever this bit changes state.

Host To Device Data Frames

This device does not accept input frames. All write attempts will fail with an error.