Chapter 15.  C50 Domain
Authors:        Luis Gutierrez
15.1  Introduction
The C50 domain generates assembly code for the Texas Instruments 
C5x series of processors. Chapter 12 describes the features 
common to all code generation domains. The basic principles of 
writing code generation stars are explained in section 12.2. You 
will find explanations for codeblocks, macros, and attributes 
there. This chapter explains features specific to the C50 
domain. Refer to the C50 chapter in the user manual for an 
introduction to these domains.

15.2  Data Types 
The supported CG50 data types are:
int
intarray
fix
fixarray
In addition the complex data type is supported for portholes 
(but not states). A complex number is stored as a sequence of 
two 16 bit numbers. The real part is stored at the lower 
address. 

15.3  Attributes 
In addition to the code generation attributes detailed in 
12.2.6, for C50 attributes are defined to specify the Single 
Access RAM and Double Access RAM memory banks. They are:

A_BMEM  Allocate this state in the address range specified by 
the bMemMap target parameter.
A_UMEM  Allocate this state in the address range specified by 
the uMemMap target parameter.
The underlying bits are AB_BMEM, and AB_UMEM. Each attribute 
above turns one off and turns the other on (e.g. A_BMEM turns 
AB_BMEM on and AB_UMEM off). 

Also for C50 stars, portholes can assert attributes P_BMEM and 
P_UMEM, which work in exactly the same way as A_BMEM and A_UMEM. 
The default attribute for a C50 porthole is P_BMEM, which 
allocates the porthole buffer in DARAM memory. Specifying the 
P_UMEM attribute places the porthole buffer in SARAM memory. 

15.4  Code Streams
The C50 domain uses the default assembly language code streams 
discussed in "Assembly code streams" on page 12-17. 
Additionally, TITarget declares a code stream named TISuProcs to 
store code that should be placed outside the main loop. Note 
that the code stored in this code stream will get added after 
the wrapup methods of the stars have been called. The TISuProcs 
code stream is useful for adding procedures when using non-COFF 
assemblers (like the TI DSK assembler) or defining tables of 
coefficients in program memory (as an example, the C50 
instruction macd needs one of the operands to be in program 
memory)

15.5  Symbols
The DSKC50 targets defines certain symbols that are meant to be 
unique. They are AIC_INIT, SETUPX, SETUPR, XINT, RINT and TINT . 
The C50Sin star defines a global symbol SINTBL used to store a 
sine table that is shared by all C50Sin stars. The user should 
avoid redefining these symbols in the output assembly file.

15.6  Reserved Memory
The DSKC50 target reserves the last 9 words in DARAM block 1 to 
store data needed to configure the Analog Interface Chip in the 
DSK board