7.3.4.8 OCI Single Step Mode

OCI Single Step mode, also known as Programming mode, is used to execute instructions from the debugger, typically for the purposes of programming the device. This mode is enabled when the debugger issues the DebugStepOCI JTAG instruction. Each instruction is fed into the CPU by writing it into the result register.

When device programming is being done over the OCI, the DebugPswrOn JTAG instruction may be issued to re-direct External Data Writes to Program Memory. The DebugPswrOff JTAG instruction may be issued to disable this re-direction. On this device, which presents a unified Program/Data memory, this re-direction is not necessary, as the Program RAM can be written via the external data bus.