Datasheet

N2HETx

178

RM57L843

SPNS215C –FEBRUARY 2014–REVISED JUNE 2016

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7.6 Enhanced High-End Timer (N2HET)

The N2HET is an advanced intelligent timer that provides sophisticated timing functions for real-time

applications. The timer is software-controlled, using a reduced instruction set, with a specialized timer

micromachine and an attached I/O port. The N2HET can be used for pulse width modulated outputs,

capture or compare inputs, or general-purpose I/O.. It is especially well suited for applications requiring

multiple sensor information and drive actuators with complex and accurate time pulses.

7.6.1 Features

The N2HET module has the following features:

• Programmable timer for input and output timing functions

• Reduced instruction set (30 instructions) for dedicated time and angle functions

• 256 words of instruction RAM protected by parity

• User defined number of 25-bit virtual counters for timer, event counters and angle counters

• 7-bit hardware counters for each pin allow up to 32-bit resolution in conjunction with the 25-bit virtual

counters

• Up to 32 pins usable for input signal measurements or output signal generation

• Programmable suppression filter for each input pin with adjustable limiting frequency

• Low CPU overhead and interrupt load

• Efficient data transfer to or from the CPU memory with dedicated High-End-Timer Transfer Unit (HTU)

or DMA

• Diagnostic capabilities with different loopback mechanisms and pin status readback functionality

7.6.2 N2HET RAM Organization

The timer RAM uses 4 RAM banks, where each bank has two port access capability. This means that one

RAM address may be written while another address is read. The RAM words are 96-bits wide, which are

split into three 32-bit fields (program, control, and data).

7.6.3 Input Timing Specifications

The N2HET instructions PCNT and WCAP impose some timing constraints on the input signals.

Figure 7-14. N2HET Input Capture Timings