NXP Semiconductors MPC5644A, Reference Manual, Page: 1693 / 1735

Development Trigger Semaphore (DTS)
MPC5644A Microcontroller Reference Manual, Rev. 6
Freescale Semiconductor 1693
Chapter 38
Development Trigger Semaphore (DTS)
38.1 Introduction
Devices in the MPC5644A family
1
include a system development feature, the Development Trigger
Semaphore (DTS) module, that enables software to signal an external tool by driving a persistent (affected
only by reset or an external tool) signal on an external device pin. There are a variety of ways this module
can be used, including as a component of an external real-time data acquisition system
2
.
38.2 Overview
The Development Trigger Semaphore (DTS) module consists of three registers and a small amount of
combinational logic to generate an output signal—DTS Trigger Output (DTO). The registers are as
follows.
• DTS_SEMAPHORE register—Any bit in this 32-bit register, when set to a value of logic ‘1’,
causes the DTS module output signal to be asserted, enabling an external tool to detect up to 32
signals from the application software. In an application, each bit is generally associated with a
specific data set.
Only the processor core and DMA module can set bits in this register. The bits can only be cleared
by a tool access via Nexus Read/Write Access over the JTAG port.
• DTS_STARTUP register—This register provides a mechanism for the external tool to notify
software running on the CPU that the tool is connected and can provide information about either
the type of tool or options that can be used by the software.
• DTS_ENABLE register—This register provides an enable/disable capability for the DTS feature.
The architecture is shown in Figure 38-1 .
Figure 38-1. DTS block diagram
1. Revision 2 and later
2. When used as a component of a triggered data acquisition system, Nexus read/write access is via the JTAG interface of the
Nexus debug port and is different than the data acquisition protocol defined in the IEEE-ISTO 5001-2003 or IEEE-ISTO
5001-2010 Nexus standards, which use the Nexus Auxiliary port.
DTS_EN
DTS_SEMPAPHORE
32-bit
DTS_ENABLE
System Clock
System Reset
XBAR Master ID
Peripheral Bus
(DTO)
DTS_STARTUP
DTS Trigger Output