MCIMX286CVM4B Freescale Semiconductor, MCIMX286CVM4B Datasheet - Page 1086

• Manufacturer Part Number: MCIMX286CVM4B
• Description: IC MPU I.MX286 289MAPBGA
• Manufacturer: Freescale Semiconductor
• Series: i.MX28r

Specifications of MCIMX286CVM4B

• Core Processor: ARM9
• Core Size: 32-Bit
• Speed: 454MHz
• Connectivity: CAN, EBI/EMI, Ethernet, I²C, MMC, SmartCard, SPI, SSI, UART/USART, USB OTG
• Peripherals: DMA, I²S, LCD, POR, PWM, WDT
• Program Memory Size: 128KB (32K x 32)
• Program Memory Type: Mask ROM
• Ram Size: 32K x 32
• Voltage - Supply (vcc/vdd): 1.25 V ~ 5.25 V
• Data Converters: A/D 17x12b
• Oscillator Type: External
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 289-LFBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Number Of I /o: -
• Eeprom Size: -
• Lead Free Status / Rohs Status: Compliant

EMI Multi-Port Arbiter
higher priority port will actually be held off for potentially several cycles. In this situation,
even though the core logic bandwidth is being utilized well, the latency requirements of the
higher priority port are not being met. The arb_cmd_q_threshold parameter is used to limit
the bandwidth overflow and prevent this condition. It ensures that a certain number of slots
remain available in the command queue for other ports. As a result, bandwidth overflow
will be allowed as long as there are less than arb_cmd_q_threshold number of entries in the
command queue.
14.5.6 Priority Round-Robin Arbitration Summary
The MC priority round-robin arbitration system combines the concepts of round-robin
operation, priority, bandwidth, and port bandwidth hold-off. The incoming commands are
separated into priority groups based on the priority of the associated port for that type of
command. Within each priority group, the Arbiter evaluates the requesting ports, the
command queue, the priority of the requests, the bandwidth being used and the overflow
option to determine the winner of the arbitration.
The order of steps is as follows:
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1. Is the core logic command queue full?
2. For all requests at each priority level, use round-robin arbitration to select a request for
3. For the highest priority port that is selected, has the bandwidth allocation for this port
4. Is bandwidth overflow enabled?
5. Are the overflow conditions met?
6. Once a request wins arbitration, it is processed into the command queue and the
that priority level.
been exceeded?
round-robin counter is updated to the next port in the circular queue.
• Yes: No further action is taken.
• No: Review the ports.
• No: This request wins arbitration. Move to step 6.
• Yes: Check the bandwidth overflow status.
• No: Repeat step 3 for the next highest priority request.
• Yes: Check the conditions for overflow.
• No: Repeat step 3 for the next highest priority request.
• Yes: This request wins arbitration.
i.MX28 Applications Processor Reference Manual, Rev. 1, 2010
Freescale Semiconductor, Inc.