MC68332ACEH20 Datasheet, PDF (52/88 Pages) Freescale Semiconductor, Inc – 32-Bit Modular Microcontroller

Freescale Semiconductor, Inc.
5 Time Processor Unit
The time processor unit (TPU) provides optimum performance in controlling time-related activity. The
TPU contains a dedicated execution unit, a tri-level prioritized scheduler, data storage RAM, dual-time
bases, and microcode ROM. The TPU controls 16 independent, orthogonal channels, each with an as-
sociated I/O pin, and is capable of performing any microcoded time function. Each channel contains
dedicated hardware that allows input or output events to occur simultaneously on all channels.
HOST
INTERFACE
CONTROL
SCHEDULER
SERVICE REQUESTS
TIMER
CHANNELS
SYSTEM
CONFIGURATION
TCR1
CHANNEL 0
CHANNEL 1
T2CLK
TCR2
DEVELOPMENT
IMB
SUPPORT AND TEST
PINS
MICROENGINE
CHANNEL
CONTROL
DATA
CONTROL
STORE
CONTROL AND DATA
PARAMETER
RAM _DATA
EXECUTION
UNIT
CHANNEL 15
Figure 12 TPU Block Diagram
TPU BLOCK
5.1 MC68332 and MC68332A Time Functions
The following paragraphs describe factory-programmed time functions implemented in standard and
enhanced standard TPU microcode ROM. A complete description of the functions is beyond the scope
of this summary. Refer to Using the TPU Function Library and TPU Emulation Mode (TPUPN00/D) as
well as other TPU programming notes for more information about specific functions.
5.1.1 Discrete Input/Output (DIO)
When a pin is used as a discrete input, a parameter indicates the current input level and the previous
15 levels of a pin. Bit 15, the most significant bit of the parameter, indicates the most recent state. Bit
14 indicates the next most recent state, and so on. The programmer can choose one of the three fol-
lowing conditions to update the parameter: 1) when a transition occurs, 2) when the CPU makes a re-
quest, or 3) when a rate specified in another parameter is matched. When a pin is used as a discrete
output, it is set high or low only upon request by the CPU.
MOTOROLA
52
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MC68332
MC68332TS/D