Architecture and Instruction Set of the C6x Processor - Digital Signal Processing and Applications with the C6713 and C6416 DSK - page 77

FIGURE 3.2. Internal memory configuration of L2 (Courtesy of Texas Instruments).
functional units consist of four floating/fixed-point ALUs (two .L and two .S ), two
fixed-point ALUs ( .D units), and two floating/fixed-point multipliers ( .M units).
Each functional unit can read directly from or write directly to the register file
within its own path. Each path includes a set of sixteen 32-bit registers, A0 through
A15 and B0 through B15. Units ending in 1 write to register file A, and units ending
in 2 write to register file B.
Two cross-paths ( 1x and 2x ) allow functional units from one data path to access
a 32-bit operand from the register file on the opposite side. There can be a maximum
of two cross-path source reads per cycle. Each functional unit side can access data
from the registers on the opposite side using a cross-path (i.e., the functional units
on one side can access the register set from the other side). There are 32 general-
purpose registers, but some of them are reserved for specific addressing or are used
for conditional instructions.