MPC555 / MPC556
TIME PROCESSOR UNIT 3
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
17-1
SECTION 17
TIME PROCESSOR UNIT 3
The time processor unit 3 (TPU3), an enhanced version of the original TPU, is an in-
telligent, semi-autonomous microcontroller designed for timing control. The TPU3 is
fully compatible to the TPU2. Operating simultaneously with the CPU, the two TPU3
modules process micro-instructions, schedules and processes real-time hardware
events, performs input and output, and accesses shared data without CPU interven-
tion. Consequently, for each timer event, the CPU setup and service times are mini-
mized or eliminated.
The MPC555 / MPC556 contains two independent TPU3s.
is a simplified
block diagram of a single TPU3.
Figure 17-1 TPU3 Block Diagram
17.1 Overview
The TPU3 can be viewed as a special-purpose microcomputer that performs a pro-
grammable series of two operations, match and capture. Each occurrence of either op-
eration is called an event. A programmed series of events is called a function. TPU
functions replace software functions that would require CPU interrupt service.
PINS
SERVICE REQUESTS
DATA
TCR1
TCR2
MICROENGINE
CONTROL
STORE
EXECUTION
UNIT
IM
B3
HOST
INTERFACE
PARAMETER
RAM
CHANNEL
CONTROL
DEVELOPMENT
SUPPORT AND
SYSTEM
CONFIGURATION
SCHEDULER
CONTROL AND DATA
CONTROL
TIMER
CHANNELS
CHANNEL 0
CHANNEL 1
CHANNEL 15
CH
A
NNEL
DATA
T2CLK
PIN
TEST
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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