Élan™SC520 Microcontroller User’s Manual
24-1
CHAPTER
24
SYSTEM TEST AND DEBUGGING
24.1
OVERVIEW
This chapter describes various system-level test features included in the ÉlanSC520
microcontroller. These features are useful for debugging hardware and software in an
ÉlanSC520 microcontroller-based system. Some of the system-level debugging features
are useful in conjunction with the AMDebug interface for software debugging. This
functionality is described in Chapter 26, “AMDebug™ Technology”.
The list below summarizes the functionality that has been included in the ÉlanSC520
microcontroller to facilitate system-level debugging.
■
A simple three-pin interface to aid in-circuit emulation tools with tracing external bus
activity
■
A write buffer test mode to assist in determining which bus masters contributed to the
current active write buffer write cycle on the SDRAM interface
■
A nonconcurrent arbitration mode that reduces the complexity of system transactions
when the Am5
x
86 CPU or PCI bus masters or GP-DMA cycles occur simultaneously
■
Echoing internal cycles and read data on the GP bus during Am5
x
86 CPU accesses of
internal integrated peripherals
■
Disabling the Am5
x
86 CPU’s integrated cache controller, controlling the cache write
policy, and specifying noncacheable memory regions
■
Controlling the clock speed of the Am5
x
86 CPU’s internal core
■
Disabling the SDRAM read buffer and write buffer
■
Ability to interrupt the Am5
x
86 CPU when an illegal memory write occurs to a write-
protected memory region, or to cause an exception when a code fetch occurs from data
memory
■
Ability to identify the source of a reset event
■
Ability to trace Error Correcting Code (ECC) errors for testing
■
Ability to override the ECC syndrome code
24.2
SYSTEM DESIGN
As shown in Table 24-1, three debugging pins on the ÉlanSC520 microcontroller operate
as either CF_DRAM, DATASTRB, and CF_ROM_GPCS, or WBMSTR2
±
WBMSTR0,
depending on if the ÉlanSC520 microcontroller has been configured for system test mode
(default) or write buffer test mode.
The CFG2–CFG0 pinstrap functions associated with these three pins are sampled only as
a result of PWRGOOD assertion and do not affect the other functions of these pins, so they
are not shown in this table. When enabled, the multiplexed signals shown in Table 24-1
either disable or alter any other function that uses the same pin.
Содержание Elan SC520
Страница 1: ...lan SC520 Microcontroller User s Manual Order 22004A...
Страница 4: ...iv lan SC520 Microcontroller User s Manual...
Страница 28: ...Introduction xxviii lan SC520 Microcontroller User s Manual...
Страница 42: ...Architectural Overview 1 14 lan SC520 Microcontroller User s Manual...
Страница 78: ...System Initialization 3 22 lan SC520 Microcontroller User s Manual...
Страница 108: ...Clock Generation and Control 5 10 lan SC520 Microcontroller User s Manual...
Страница 118: ...Reset Generation 6 10 lan SC520 Microcontroller User s Manual...
Страница 148: ...System Arbitration 8 24 lan SC520 Microcontroller User s Manual...
Страница 214: ...SDRAM Controller 10 36 lan SC520 Microcontroller User s Manual...
Страница 230: ...Write Buffer and Read Buffer 11 16 lan SC520 Microcontroller User s Manual...
Страница 288: ...GP Bus DMA Controller 14 22 lan SC520 Microcontroller User s Manual...
Страница 316: ...Programmable Interval Timer 16 8 lan SC520 Microcontroller User s Manual...
Страница 328: ...Software Timer 18 4 lan SC520 Microcontroller User s Manual...
Страница 346: ...Real Time Clock 20 12 lan SC520 Microcontroller User s Manual...
Страница 360: ...UART Serial Ports 21 14 lan SC520 Microcontroller User s Manual...
Страница 414: ...AMDebug Technology 26 8 lan SC520 Microcontroller User s Manual...