PicC 9.50 dsPIC Manual.pdf

C Language FeaturesSupported Data Types and Variablesstruct {unsigned lo : 1;unsigned dummy : 14;unsigned hi : 1;} foo;will produce a structure occupying 2 bytes. If foo was ultimately linked at address 10H, the field lowill be bit 0 of address 10H, hi will be bit 7 of address 11H. The least significant bit of dummy willbe bit 1 of address 10H and the most significant bit of dummy will be bit 6 of address 11h.Unnamed bit-fields may be declared to pad out unused space between active bits in controlregisters. For example, if dummy is never used the structure above could have been declared as:struct {unsigned lo : 1;unsigned : 14;unsigned hi : 1;} foo;If a bit-field is declared in a structure that is assigned an absolute address, no storage will be allocatedfor the structure. Absolute structures would be used when mapping a structure over a register to allowa portable method of accessing individual bits within the register.A structure with bit-fields may be initialised by supplying a comma-separated list of initial valuesfor each field. For example:struct {unsigned lo : 1;unsigned mid : 14;unsigned hi : 1;} foo = {1, 8, 0};3.4.7.2 Structure and Union QualifiersHI-TECH C supports the use of type qualifiers on structures. When a qualifier is applied to a structure,all of its members will inherit this qualification. In the following example the structure isqualified const.const struct {int number;int *ptr;} record = { 0x55, &i};35