This section describes the features supplied by the PCIe controller modules (including PCIe at device level). The PCIe_SS1 and PCIe_SS2 controllers comply with the following standards:
- PCI Local Bus Specification revision 3.0
- PCI Express Base 3.0 Specification, revision 1.0.
At system level the device supports PCI express interface in the following configurations:
- Each PCIe subsystem controller has support for PCIe Gen2 mode (5.0 Gbps per lane) and Gen1 mode (2.5 Gbps per lane).
- One PCIe (PCIe_SS1) operates as Gen2 2-lanes supporting in either root-complex (RC) or end-point EP.
- Two PCIe (PCIe_SS1 and PCIe_SS2) operates Gen2 1-lane supporting either RC or EP with the possibility of one operating in Gen1 and one in Gen2.
- PCIe_SS1 can be configured to operate in either 2-Lane (dual lane) or 1-Lane (single lane) mode, as follows:
- Single Lane - lane 0 mapped to the PCIe port 0 of the device
- Flexible dual lane configuration - lanes 0 and 1 can be swapped on the two PCIe ports
- PCIe_SS2 can only operate in 1-Lane mode, as follows:
- Single Lane - lane 0 mapped to the device PCIe port 1
When PCie_SS1 is configured to operate in dual-lane mode, PCIe_SS2 is not available.
The main features of a device PCIe controller are:
- 16-bit operation at 250 MHz on PIPE interface (per 16-bit lane)
- One master port on the L3_MAIN supporting 32-bit address and 64-bit data bus.
- PCIe_SS1/PCIe_SS2 master port dedicated MMU (device MMU2) on L3_MAIN path, to which PCIe traffic can be optionally mapped.
- One slave port on the L3_MAIN supporting 29-bit address and 64-bit data bus.
- Maximum outbound payload size of 64 Bytes (the L3 Interconnect PCIe1/2 target ports split bursts of size >64 Bytes to the into multiple 64 Byte bursts)
- Maximum inbound payload size of 256 Bytes (internally converted to 128 Byte - bursts)
- No remote read request size limit: implicit support for 4 KiB-size and greater
- Support of EP legacy mode
- Support of inbound I/O accesses in EP legacy mode
- PIPE interface features fixed-width (16-bit data per lane) and dynamic frequency to switch between PCIe Gen1 and Gen2.
- Ultra-low transmit and receive latency
- Automatic Lane reversal as specified in the PCI Express Base 3.0 Specification, revision 1.0 (transmit and receive)
- Polarity inversion on receive
- Single Virtual Channel (VC0) and Single Traffic Class (TC0)
- Single Function in End point mode
- Automatic credit management
- ECRC generation and checking
- All PCI Device Power Management D-states with the exception of D3cold/L2 state
- PCI Express Active State Power Management (ASPM) state L0s and L1 (with exceptions)
- PCI Express Link Power Management states except for L2 state
- PCI Express Advanced Error Reporting (AER)
- PCI Express messages for both transmit and receive
- Filtering for Posted, Non-Posted, and Completion traffic
- Configurable BAR filtering, I/O filtering, configuration filtering and completion lookup/timeout
- Access to configuration space registers and external application memory mapped registers through ECAM mechanism.
- Legacy PCI Interrupts reception (RC) and generation (EP)
- 2× hardware interrupts per PCIe_SS1and PCIe_SS2 controller mapped via the device Interrupt Crossbar (IRQ_CROSSBAR) to multiple device host (MPU, DSP, and so forth) interrupt controllers in the device
- MSIs generation and reception
- PCIe_PHY Loopback in RC mode