[Key Highlights – Preview]

▶ USB 2.0 High-Speed (480 Mbps) / Full-Speed (12 Mbps) – Certified by USB-IF Compatibility Test

▶ Enhanced 8051 core with 4 clock cycles per instruction – at 48 MHz, this is three times the standard 8051 clock speed.

▶ 16K on-chip SRAM – firmware can be downloaded via USB or loaded via I2C EEPROM

▶ SlaveFIFO/PIF high-speed data channel – achieves throughput exceeding 50 MB/s within the firmware framework

I. Core Performance and USB Features

Q1: What USB speeds does the CBM9002A support, and is its compatibility guaranteed?

A: Supports both USB 2.0 high-speed (480 Mbps) and full-speed (12 Mbps) modes; features an integrated USB 2.0 transceiver and intelligent serial interface engine; has passed the USBIF USB 2.0 compatibility test.

Selection Tip: Before mass production, request a USBIF test report for verification; the eye diagram margin directly impacts the tolerance allowances for cables and PCB traces – the larger the margin, the more robust the design.

Q2. How many USB endpoints are there inside the chip? How should they be allocated?

A: The CBM9002A provides a total of 7 endpoints; EP0 is dedicated to control transfers, used for enumeration and standard requests (as required by the USB protocol); the transfer types for EP1IN/EP1OUT and EP2/EP4/EP6/EP8 are configured by the firmware descriptor and can be assigned as interrupt or batch transfers; large data blocks are handled via the batch endpoint.

Selection Tip: For high-throughput applications, route the main data stream to endpoints configured for batch processing; reserve interrupt endpoints for state-related information to prevent interference with bandwidth usage.

II. Core Architecture and Development

Q3. What makes the Enhanced 8051 core superior to the Standard 8051 core?

A: Operates at 48 MHz, 24 MHz, or 12 MHz; each instruction cycle consists of 4 clock cycles; at 48 MHz, the instruction throughput is approximately three times that of the standard 8051 microcontroller; the standard 8051 programming model is retained; features include 2 UARTs, 3 16-bit timers/counters, 2 data pointers, an extended interrupt system, and a vector-based USB interrupt mechanism.

Selection tip: The cost of migrating firmware from the standard 8051 architecture is low; however, note that the device lacks built-in ROM – the code must be executed in the 16 KB SRAM of the microcontroller.

Q4. What is the size of the memory, and how is the firmware loaded?

A: An on-chip 16 KB code/data SRAM plus 0.5 KB data RAM. The firmware can be downloaded via USB or loaded from an external EEPROM using the on-chip I2C interface; the hardware handles the boot process automatically.

Selection Tip: For mass production, use EEPROM loading – connect a compatible device to the I2C bus and verify its address and speed; USB downloading is suitable for development and debugging phases.

Q5: How is the chip's firmware program loaded? Will it be lost after a power outage?

A: We offer two flexible firmware loading methods that balance development convenience with mass-production stability:

l USB Download: Directly download the firmware to the 16 KB of internal RAM on the chip via the USB interface – ideal for development and debugging phases.

l EEPROM loading: The firmware is stored in an external EEPROM and is automatically loaded by the hardware upon power-up. With this approach, the firmware remains intact even after a power loss; it is therefore the recommended solution for mass-produced products.

Selection Tip: For mass production, it is recommended to use EEPROM loading; in this case, a compatible device should be connected to the I2C bus, and its address and speed should be verified.

Q6: What is the size of the chip's storage capacity?

A: The CBM9002A features ample on-chip memory resources to support high-speed data buffering and complex applications:

l 16 KB SRAM: Can be used as code or data memory.

l Additional 0.5 KB of Data RAM.

III. Interfaces and Electrical Characteristics

Q7. How does the CBM9002A's SlaveFIFO work?

A: The external master controller (FPGA, ASIC, DSP) directly reads from or writes to the endpoint FIFO via a 16-bit data bus; this operation is governed by signal handshake protocols such as SLOE, SLRD, SLWR, FIFOADR, and FLAG, ensuring that data is not transferred via the CPU; the interface supports both master/slave device mode and synchronous or asynchronous operation; the 16-bit bus can automatically switch to a two-byte mode.

Selection Tip: The synchronous mode is driven by the IFCLK clock, providing more stable throughput; the asynchronous mode has less stringent clock requirements and is suitable for the FPGA side that already features asynchronous interfaces.

Q8. What problems does the PIF Programmable Interface address?

A: The PIF uses a programmable waveform descriptor to define bus timing; when combined with the RDY ready input and CTL control output, it can be directly connected to most parallel peripheral interfaces without requiring the CPU to simulate the timing on a byte-by-byte basis.

Selection Tip: When connecting parallel peripherals that do not support a standard FIFO interface, prioritize using PIF; the four waveform descriptors can accommodate a variety of access modes.

Q9. How is a throughput of 50 MB/s or higher achieved?

A: Under the firmware framework provided by Xinbaiwei, the data plane is handled by the SlaveFIFO/PIF hardware, while the CPU is solely responsible for configuration and control; when combined with batch endpoints and a 16-bit bus, the measured throughput can exceed 50 MB/s, with the maximum limit being the USB 2.0 bandwidth.

Selection Note: Actual throughput is influenced by endpoint configuration, host driver, and firmware framework version; therefore, conduct a practical measurement and evaluation based on the target rate at the time of project initiation.

Q10. In addition to USB, which other common interfaces are integrated into the chip? How many GPIO pins are there?

A: In addition to its powerful USB functionality, the CBM9002A integrates a comprehensive range of peripheral resources, meeting the expansion requirements of most applications.

Selection Note: The I2C interface does not support the Slave mode. The number of GPIO pins is closely dependent on the device package; for example, a 56-pin package (SSOP / QFN / BGA) contains only 24 IO pins – please take this into account when selecting a device.

Q11. What are the requirements for power supply and voltage level?

A: Recommended supply voltage: 3.0–3.6 V (typical: 3.3 V); the IO input voltage can tolerate a 5.0 V tolerance; input high level ≥ 2.0 V, input low level ≤ 0.8 V; minimum output high level: 2.4 V (IOH = 4 mA); ESD (Electrostatic Discharge) voltage: 2000 V; dissipation power: 300 mW.

Model Selection Note: 3.3 V main power supply; 5 V tolerant input – when directly connected to 5 V peripherals, pay attention to the polarity and sourcing current; the output side should be evaluated based on a 4 mA current capability.

Q12. How does the chip's power consumption perform? Is it suitable for battery-powered portable devices?

A: Highly suitable. In the CBM9002's idle mode, power consumption does not exceed 1 mA; in the high-speed operation mode (8051 processor running), the supply current is typically 37 mA and up to 44 mA; in any mode, the supply current does not exceed 85 mA.

Selection Tip: For battery-powered applications, pay attention to the suspend current; USB device suspension is triggered by the bus – ensure the wake-up source (WAKEUP input) is properly configured.

Q13. How do you configure the chip's clock?

A: An external 24 MHz (±100 ppm) parallel resonant crystal oscillator is connected to XTALIN/XTALOUT; the CLKOUT pin can output 12/24/48 MHz clocks and supports tri-state configuration.

Selection Tip: A crystal oscillator accuracy of 100 ppm is critical for minimizing jitter at both USB Full-Speed and High-Speed modes; position the PCB layout as close as possible to the chip, and ensure the crystal and load capacitor are configured for parallel resonant matching.

Q14. What are the available temperature ranges, packaging options, and ordering models?

A: The operating temperature range is 0–70°C (SCG/BCG/LCG/TCG) and −40–105°C (ISG/IBG/ILG/TIG); available package options include SSOP56, QFN56, VFBGA56, and LQFP100; packaging available in tube or pallet format, with quantities ranging from 390 to 2600 units.

IV. Product Selection and Application

Q15. Which products are most suitable for the CBM9002A?

A: Data acquisition system; industrial cameras/video surveillance; VGA video capture and transmission; card reader; scanner; laser engraving equipment; ATA interface (IDE hard drive); portable sound card/MP3 player; sensor applications.

Selection Tip: For big data scenarios such as video streaming or data acquisition streams, prioritize SlaveFIFO; for peripheral bridging scenarios, prioritize PIF; for pure low-speed control scenarios, the standard 8051 series is sufficient.

Q16. What package types and temperature ratings are available for the CBM9002A?

A: We offer a wide range of packaging options and temperature ratings to meet the requirements of various application scenarios.

Model Selection Summary

The CBM9002A integrates an enhanced 8051 programming model, a USB 2.0 transceiver, and a SlaveFIFO/PIF high-speed interface into a single device, making it ideal for designs requiring high-speed communication with a host – such as data acquisition, video transmission, and peripheral bridging applications.