The **PL-USB-BLASTER-R** is a specific revision/model of the Altera (now Intel) USB-Blaster Download Cable. It serves as a hardware interface to bridge a PC's USB port to a target FPGA or CPLD on a printed circuit board. ### 1. Key Internal Electronic Components The device is generally composed of three primary electronic stages: | Component Category | Typical Part(s) Used | Function | | :--- | :--- | :--- | | **USB Controller** | FTDI FT245RL / FT245BL | Converts USB signals into a parallel data stream for the logic controller. | | **Logic Controller** | Altera CPLD (e.g., MAX II or MAX 7000) | Manages the JTAG state machine and timing requirements for data transmission. | | **Level Shifters** | 74LVC244 / 74LVC125 | Buffers the signals and adjusts voltage levels (1.5V to 5.0V) to match the target board. | --- ### 2. Functional Specification The "R" in the part number often refers to the **RoHS compliant** version of the Rev. B or Rev. C hardware. * **Interface Protocols:** Supports JTAG, Passive Serial (PS), and Active Serial (AS) programming modes. * **Target Voltage:** Operates across a wide range, typically supporting **1.5V, 1.8V, 2.5V, 3.3V, and 5.0V** logic. * **Speed:** USB 2.0 Full Speed (12 Mbps). While it connects via USB 2.0, the actual JTAG clock (TCK) is usually limited to ~6 MHz. --- ### 3. Pinout Configuration (10-Pin Header) The output is a standard 2x5 (0.1") female ribbon cable connector. | Pin | Signal | Description | | :--- | :--- | :--- | | 1 | **TCK** | Test Clock | | 2 | **GND** | Ground | | 3 | **TDO** | Test Data Out | | 4 | **VCC (TRGT)** | Target Power (Senses voltage level) | | 5 | **TMS** | Test Mode Select | | 6 | **N.C.** | No Connection | | 9 | **TDI** | Test Data In | | 10 | **GND** | Ground | --- ### 4. Hardware Limitations and Notes * **Power Source:** The USB-Blaster is powered by the USB port, but it requires the target board's $V_{CC}$ to be connected to Pin 4 to sense the I/O voltage level for the level shifters. * **Drivers:** It requires the **Intel FPGA Download Cable** driver, which is bundled with the Quartus Prime software suite. ---