User’s Manual
44
5.2
Dynamic C Function Calls
5.2.1 Digital I/O
The RCM4510W was designed to interface with other systems, and so there are no drivers written
specifically for the Rabbit 4000 I/O. The general Dynamic C read and write functions allow you
to customize the parallel I/O to meet your specific needs. For example, use
WrPortI(PEDDR, &PEDDRShadow, 0x00);
to set all the Port E bits as inputs, or use
WrPortI(PEDDR, &PEDDRShadow, 0xFF);
to set all the Port E bits as outputs.
When using the external I/O bus on the Rabbit 4000 chip, add the line
#define PORTA_AUX_IO
// required to enable external I/O bus
to the beginning of any programs using the external I/O bus.
The sample programs in the Dynamic C
SAMPLES/RCM4500W
folder provide further examples.
5.2.2 Serial Communication Drivers
Library files included with Dynamic C provide a full range of serial communications support.
The
RS232.LIB
library provides a set of circular-buffer-based serial functions. The
PACKET.LIB
library provides packet-based serial functions where packets can be delimited by the
9th bit, by transmission gaps, or with user-defined special characters. Both libraries provide
blocking functions, which do not return until they are finished transmitting or receiving, and non-
blocking functions, which must be called repeatedly until they are finished, allowing other func-
tions to be performed between calls. For more information, see the
Dynamic C Function
Reference Manual
and Technical Note TN213,
Rabbit Serial Port Software
.
5.2.3 User Block
Certain function calls involve reading and storing calibration constants from/to the simulated
EEPROM in flash memory located at the top 2K of the reserved user block memory area (3800–
39FF). This leaves the address range 0–37FF in the user block available for your application.
These address ranges may change in the future in response to the volatility in the flash memory
market, in particular sector size. The sample program
USERBLOCK_INFO.C
in the Dynamic C
SAMPLES\USERBLOCK
folder can be used to determine the version of the ID block, the size of
the ID and user blocks, whether or not the ID/user blocks are mirrored, the total amount of flash
memory used by the ID and user blocks, and the area of the user block available for your applica-
tion.
The
USERBLOCK_CLEAR.C
sample program shows you how to clear and write the contents of
the user block that you are using in your application (the calibration constants in the reserved area
and the ID block are protected).
