Maxim Integrated Secure Microcontroller - Manual (Page 141)

Secure Microcontroller User’s Guide
141 of 187
16.5 Serial Program Load Mode
The serial bootstrap loader is the easiest method of loading application software into the NV RAM.
Communication can be performed over a standard asynchronous serial communications port using a
terminal emulator program with 8-N-1 (8 data bits, no parity, 1 stop bit) protocol settings. A typical
application would use a simple RS232C serial interface to program the device as part of a final
production procedure.
The hardware configuration for the Serial Program Load mode is illustrated in
Figure 16-2 . Note that P2.7
and P2.6 must be either open or pulled up during serial programming of a DS5000 series device. Failure
to do this results in a parallel load operation. A variety of crystals can be used to produce standard baud
rates.
Table 16-A shows the baud rates that are supported using a variety of popular crystal frequencies.
The serial loader is designed to operate across a 3-wire interface from a standard UART. The receive,
transmit, and ground wires are all that are necessary to establish communication with the device.
The serial loader implements an easy-to-use command line interface that allows an Intel hex file to be
loaded and read back from the device. Intel hex is the standard format output by 8051 cross-assemblers.
Figure 16-2. Serial Load Configuration