PXS20 Datasheet, PDF (8/119 Pages) Freescale Semiconductor, Inc – PXS20 Microcontroller

Introduction
— Misaligned access support
— Single stall cycle on load to use
• Single-cycle throughput (2-cycle latency) integer 32 × 32 multiplication
• 4 – 14 cycles integer 32 × 32 division (average division on various benchmark of nine cycles)
• Single precision floating-point unit
— 1 cycle throughput (2-cycle latency) floating-point 32 × 32 multiplication
— Target 9 cycles (worst case acceptable is 12 cycles) throughput floating-point 32 × 32 division
— Special square root and min/max function implemented
• Signal processing support: APU-SPE 1.1
— Support for vectorized mode: as many as two floating-point instructions per clock
• Vectored interrupt support
• Reservation instruction to support read-modify-write constructs
• Extensive system development and tracing support via Nexus debug port
1.5.2 Crossbar Switch (XBAR)
The XBAR multi-port crossbar switch supports simultaneous connections between four master ports and three slave ports. The
crossbar supports a 32-bit address bus width and a 64-bit data bus width.
The crossbar allows four concurrent transactions to occur from any master port to any slave port, although one of those transfers
must be an instruction fetch from internal flash memory. If a slave port is simultaneously requested by more than one master
port, arbitration logic selects the higher priority master and grants it ownership of the slave port. All other masters requesting
that slave port are stalled until the higher priority master completes its transactions.
The crossbar provides the following features:
• 4 masters and 3 slaves supported per each replicated crossbar
— Masters allocation for each crossbar: e200z4d core with two independent bus interface units (BIU) for I and D
access (2 masters), one eDMA, one FlexRay
— Slaves allocation for each crossbar: a redundant flash-memory controller with 2 slave ports to guarantee maximum
flexibility to handle Instruction and Data array, one redundant SRAM controller with 1 slave port each and 1
redundant peripheral bus bridge
• 32-bit address bus and 64-bit data bus
• Programmable arbitration priority
— Requesting masters can be treated with equal priority and are granted access to a slave port in round-robin method,
based upon the ID of the last master to be granted access or a priority order can be assigned by software at
application run time
• Temporary dynamic priority elevation of masters
The XBAR is replicated for each processor.
1.5.3 Memory Protection Unit (MPU)
The Memory Protection Unit splits the physical memory into 16 different regions. Each master (eDMA, FlexRay, CPU) can be
assigned different access rights to each region.
• 16-region MPU with concurrent checks against each master access
• 32-byte granularity for protected address region
The memory protection unit is replicated for each processor.
PXS20 Microcontroller Data Sheet, Rev. 1
8
Freescale Semiconductor
Preliminary—Subject to Change Without Notice