
C-2
MPC565/MPC566 Reference Manual
MOTOROLA
Overview
The TPU3 can address up to 8 Kbytes of memory at any one time. It has 4 Kbytes of internal
ROM, located in banks 0 and 1, and 6 Kbytes of dual-ported SRAM (DPTRAM), located
in banks 0, 1, and 2. As only one type of memory can be used at a time, the TPU3 must
either use the internal ROM or the SRAM. Functions from both memory types cannot be
used in conjunction.
A new feature of the TPU3 microcode ROM is the two sixteen-function entry tables in the
4 Kbytes of internal ROM. The ETBANK field in the TPUMCR2 register, written once
after reset, determines which one of these entry tables the CPU selects. Though the TPU3
can access either entry table, only one table can be used at a time and functions from the
tables cannot be mixed. The default entry table, located in bank 0, is identical to the
standard microcode ROM in the TPU2, making any CPU code written for the TPU2
interchangable with the TPU3. The functions in the default entry table in bank 0 are listed
The functions in the bank 1 entry table are identical to those in bank 0, except in three cases.
Function 1, SPWM in the bank 0 table, has been replaced by RWTPIN, a function that
allows a read and write to the TPU3 timebases and corresponding pin. Function 5, PPWA
in the bank 0 table, is an identification function in the bank 1 table that provides the
microcode ROM revision number. Function 7, MCPWM, has been removed and left open
for future use. The functions in the bank 1 entry table are listed in
Table C-2.Table C-1. Bank 0 Functions
Function
Number
Function
0xF
PTA (Programmable Time Accumulator)
0xE
QOM (Queued Output Match)
0xD
TSM (Table Stepper Motor)
0xC
FQM (Frequency Measurement)
0xB
UART (Universal Asynchronous Receiver/Transmitter)
0xA
NITC (New Input Capture/Input Transition Counter)
9
COMM (Multiphase Motor Commutation)
8
HALLD (Hall Effect Decode)
7
MCPWM (Multi-Channel Pulse Width Modulation)
6
FQD (Fast Quadrature Decode)
5
PPWA (Period/Pulse Width Accumulator)
4
OC (Output Compare)
3
PWM (Pulse Width Modulation)
2
DIO (Discrete Input/Output)
1
SPWM (Synchronized Pulse Width Modulation)
0
SIOP (Serial Input/Output Port)