BusPirate v3.6:
http://dangerousprototypes.com/docs/Bus_Pirate_v3.6
http://dangerousprototypes.com/docs/Features_overview
It has USB <--> FT232RL <--> PIC24FJ64GA002 <--> I2C/UART/JTAG/SPI
Due to FT232RL it is only 12 MBit/s Full Speed USB 2.0. Compare with FT2232H/FT232H of TUMPA/TUMPA Lite which operate at 480 MBit/s High Speed USB 2.0.
Also FT2232H/FT232H have separate 4KiB / 1KiB buffer for read/write of its 32/16 IO lines, PIC24FJ64GA002 have nothing but 21 IO pins...
For BusPirte there are a lot of projects, like low-level logic analyzer
http://sigrok.org/wiki/Dangerous_Prototypes_Buspirate , AVR/PIC MCU programmer, bus sniffer.
In bit-bang mode FT2232H/FT232H able to listen to 16/8 lines with speed near 30 Mbit/s (but I may wrong in reading spec), so it is possible to build 10 times accurate logic analyzer.
BusPirate uses internal 64 KiB Flash for storing serial user interface for commands and macros and currently it is not possible to hold all application in that amount. So users re-flash BusPirate in order to get required application.
On other hand with FT2232H with MPSSE it is possible operate with any protocol on must higher speed and have all logic on PC side so there are no memory / CPU power limits...
AVR ISP is basically a 3 wire SPI interface, with Vcc, ground, and inverted reset:
http://dangerousprototypes.com/docs/Bus_Pirate_AVR_Programming
I wander if it may be implemented on FT2232H/FT232H TUMPA board?
On other words TUMPA is great by its hardware but lack of software/application support.
Also more powerful TUMPA doesn't expose all FT2232H pins to user, see:
http://www.tiaowiki.com/forums/index.php/topic,4122.msg5525.html#msg5525 To get full features of chip it is recommended to use TUMPA Lite (which based on FT232H).
Why we have very low interest in TUMPA and so many buzzing about BusPirate?
