Anyone know where I can find the schematic for the ARM-USB-OCD?
I would like to use the ARM-USB-OCD for an application other than debugging ARM chips. Specifically, I would like to use it as an I2C/SPI interface. The product is packaged nicely, has connectors in place and also has the FT2232 B-port configured as an RS232 device. More important for SPI, is the fact that level translation hardware appears to be present.
To use ARM-USB-OCD for my application, I really need a schemtic diagram. I could pull out my DVM and reverse-engineer it, but it would be easier if I could find the schematic on the web.
In the absence of the full schematic, the portion of the schematic from the JTAG port back to the FT2232, including any level translation and direction control, would give me what I need. How the LED is connected to the FT2232 would be useful so I can control them from my application.
Also, is anyone aware of any existing software which allows programming of SPI or I2C flash/EE PROMs using the FT2232?
urbite:
Anyone know where I can find the schematic for the ARM-USB-OCD?
I would like to use the ARM-USB-OCD for an application other than debugging ARM chips. Specifically, I would like to use it as an I2C/SPI interface. The product is packaged nicely, has connectors in place and also has the FT2232 B-port configured as an RS232 device. More important for SPI, is the fact that level translation hardware appears to be present.
To use ARM-USB-OCD for my application, I really need a schemtic diagram. I could pull out my DVM and reverse-engineer it, but it would be easier if I could find the schematic on the web.
In the absence of the full schematic, the portion of the schematic from the JTAG port back to the FT2232, including any level translation and direction control, would give me what I need. How the LED is connected to the FT2232 would be useful so I can control them from my application.
Also, is anyone aware of any existing software which allows programming of SPI or I2C flash/EE PROMs using the FT2232?
TIA
Urb
This page may give you something to help since it provides schematics of a device with a similar feature set that supports OpenOCD. Since it directly supports OpenOCD the connections between the JTAG port and the FT2232 are probably the same?
The basic mapping between SPI signals, MISO, MOSI, CLK and the JTAG signals is determined by the FT2232 MPSSE protocol and pin mapping.
TDI = MOSI
TDO = MISO
TCK = CLK
This is the same for all FT2232 based JTAG adapters. The differens is how TMS, nRST, tRST and some other interface enable/control signals are mapped.
You can look at the OpenOcd source code in jtag/ft2232.c ,where there the mapping betwen FT2232 signals and JTAG signals is implemented. Look at the function olimex_jtag_init
Note: the actuel schematic of the turtelizer could not down to 1.65V as they say ! They can down to a safe 2.8V but not the 1.65V.
Only the JTAGkey can down to a safe 1.45V and up to a safe 5.5V !
The only solution to down to 1.65V or 1.45 as the JTAGkey and allowing the 5.5V too is to use analog converter ! But you analog stage must be as fast as 5ns from 1.45V to 5.5V → not cheap as using simple logic buffer !