MSC8144E Reference Manual, Rev. 3
2-4
Freescale
Semiconductor
SC3400 Core Overview
2.1.1.1 Data Registers
The Data ALU registers are read or written over the data buses (Xa and Xb). The source operands
for Data ALU arithmetic instructions always originate from Data ALU registers. All the Data
ALU operations are performed in one clock cycle so that a new instruction can be initiated in
every clock, yielding a rate of up to four Data ALU instructions per clock cycle. The destination
of every arithmetic operation can be used as a source operand for the operation immediately
following.
2.1.1.2 Multiply-Accumulate (MAC) Unit
The MAC unit comprises the main arithmetic processing unit of each SC3400 core and performs
all the calculations on data operands. The MAC unit outputs one 40-bit result in the form of
[Extension:Most Significant Portion:Least Significant Portion] (EXT:MSP:LSP). The multiplier
executes 16-bit
×
16-bit fractional or integer multiplication between two’s complement signed,
unsigned, or mixed operands. The 32-bit product is right-justified and added to the 40-bit
contents of one of the sixteen data registers.
2.1.1.3 Bit-Field Unit (BFU)
The BFU contains a 40-bit parallel bidirectional shifter with a 40-bit input and a 40-bit output,
mask generation unit, and logic unit. The BFU is used in the following operations:
Multi-bit left/right shift (arithmetic or logical)
One-bit rotate (right or left)
Bit-field insert and extract
Count leading bits
Logical operations
Sign or zero extension operations
2.1.1.4 Back Trace Registers (BTR)
The Back Trace Registers (BTR), BTR0 and BTR1, optimize the implementation of Viterbi
encoder and decoder algorithms.
2.1.2 Address Generation Unit (AGU)
The AGU is one of the execution units in the SC3400 core. The AGU performs effective address
calculations using the integer arithmetic necessary to address data operands in memory, and it
contains the registers to generate the addresses. It performs four types of arithmetic: linear,
modulo, multiple wrap-around modulo, and reverse-carry. The AGU operates in parallel with
other chip resources to minimize address generation overhead. The AGU also generates
change-of-flow program addresses and manages the stack pointer (SP). The major components of
the AGU are as follows:
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...