Chapter 16. Programmable I/O and Watchpoint
16-1
Chapter 16
Programmable I/O and Watchpoint
The MPC8240 programmable I/O and watchpoint facility allows system designers to
monitor the state of the internal peripheral logic (interface between the processor core and
the peripheral logic block) bus and trigger an output signal as shown in Figure 16-1. The
user programs up to two sets of fully maskable 58-bit triggers called watchpoints on the
peripheral logic address and control buses. Once enabled, the watchpoint facility scans the
peripheral logic bus for a user-programmable sequence of matches to these
watchpoints.Note that the peripheral logic bus signals are analogous to the 60x bus signals
on the MPC603e and throughout this chapter, they are referenced as the corresponding
external signals in the MPC603e User’s Manual.
Figure 16-1. Watchpoint Facility Signal Interface
Each watchpoint has a dedicated, user programmable, 4-bit match count register. The value
programmed into the count register determines the number of times the associated
watchpoint must match the state of the peripheral logic bus before the watchpoint facility
generates a final match. Upon a final match, the watchpoint facility can be programmed to
generate an external trigger pulse on the TRIG_OUT signal. The watchpoint facility can be
programmed to disable itself and stop scanning (one-shot scan mode) following a trigger
pulse, or to continue to scan for the next occurrence of the trigger match (continuous scan
mode) until explicitly disabled by the user. The following features are provided by the
watchpoint facility:
MPC8240
Processor
Peripheral
Watchpoint
facility
TRIG_OUT
Peripheral
logic bus
logic block
core
TRIG_IN
Summary of Contents for MPC8240
Page 1: ...MPC8240UM D Rev 1 1 2001 MPC8240 Integrated Processor User s Manual ...
Page 38: ...xviii MPC8240 Integrated Processor User s Manual TABLES Table Number Title Page Number ...
Page 48: ...xlviii MPC8240 Integrated Processor User s Manual Acronyms and Abbreviations ...
Page 312: ...6 94 MPC8240 Integrated Processor User s Manual ROM Flash Interface Operation ...
Page 348: ...7 36 MPC8240 Integrated Processor User s Manual PCI Host and Agent Modes ...
Page 372: ...8 24 MPC8240 Integrated Processor User s Manual DMA Register Descriptions ...
Page 394: ...9 22 MPC8240 Integrated Processor User s Manual I2O Interface ...
Page 412: ...10 18 MPC8240 Integrated Processor User s Manual Programming Guidelines ...
Page 454: ...12 14 MPC8240 Integrated Processor User s Manual Internal Arbitration ...
Page 466: ...13 12 MPC8240 Integrated Processor User s Manual Exception Latencies ...
Page 516: ...16 14 Watchpoint Trigger Applications ...
Page 538: ...B 16 MPC8240 Integrated Processor User s Manual Setting the Endian Mode of Operation ...
Page 546: ...C 8 MPC8240 Integrated Processor User s Manual ...
Page 640: ...INDEX Index 16 MPC8240 Integrated Processor User s Manual ...