Chapter 15. Debug Features
15-5
Memory Debug Address
Figure 15-2. Example PCI Address Attribute Signal Timing for Burst Write
Operations
15.3 Memory Debug Address
When enabled, the debug address gives software disassemblers a simple way to reconstruct
the 30-bit physical address for a memory bus transaction to DRAM, SDRAM, ROM, Flash,
or Port X. For DRAM or SDRAM, these 16 debug address signals are sampled with the
column address and chip-selects. For ROM, Flash, and Port X devices, the debug address
pins are sampled at the same time as the ROM address and can be used to recreate the 24-bit
physical address in conjunction with ROM address. The granularity of the reconstructed
physical address is limited by the bus width of the interface; double words for 64-bit
interfaces, words for 32-bit interfaces, and bytes for 8-bit interfaces.
15.3.1 Enabling Debug Address
The debug address functionality is enabled or disabled at reset by using the GNT4 reset
configuration signal. If the GNT4 signal is left floating at reset, an internal pull-up forces it
high, disabling the debug address functionality. If GNT4 is asserted at reset (driven low),
the debug address functionality is enabled. See Section 2.4, “Configuration Signals
Sampled at Reset,” for a complete description of all the reset configuration signals.
Additionally the debug address functionality can be enabled by the setting of the
DEBUG_ADDR_ bit in the WP_CONTROL register. See Section 16.2.4, “Watchpoint
Control Register (WP_CONTROL),” for more information.
PCI_CLK[0:4]
FRAME
IRDY
AD[31:0]
ADDR
DEVSEL
TRDY
PMAA[0:2]
VALID
C/BE[3:0]
b’111’
DATA1
DATA2
DATA3
DATA4
T/A
CMD
Byte Enables 1 Byte Enables 2 Byte Enables 3 BEs 4
T/A
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 ...