Gxb - Intel 460GX Software Developer’s Manual

Register Descriptions
5:0
2.5.4

GXB

2.5.4.1 AGP_PMD_0,1: AGP Performance Monitor Data Registers
Function Number:
Address Offset:
Default Value:
Sticky:
This counter may be configured to track AGP bus events as well as events internal to the GXB.
Event detection may be configured to increment a counter, affect performance monitoring pins, and
issue an interrupt request on counter overflow.
The value written to this address, loads the counter and is also saved in a reload register. Each
counter can be configured to reload the data.
The AGP_G_PMD register holds the performance monitoring count value. 39-bits of the counter
are used for event counting, the 40th-bit is used as a overflow detection bit. The 39-bit count value
allows up to 70 minutes of event collection at 133 MHz. Event selection is controlled by the PMC
registers.
Each counter may be stopped/started independently, using the controls available in the associated
PMD register.
Bits
63:40
39
2-38
Event Selection
This field specifies the basic PCI bus transaction or PCI bus signal to be monitored.
Individual Bus Transactions
00 0000 reserved
00 0001 reserved
00 0010 I/O Read
00 0011 I/O Write
00 0100 reserved
00 0101 reserved
00 0110 Memory Read
00 0111 Memory Write
Generic (Grouped) Bus Transactions
010 000 Any bus transaction
010 001 Any memory transaction
010 010 Any memory read
010 011 Any memory write
Bus Signal Assertions
011 000 reserved
011 001 reserved
1
011 010 RETRY
011 011 reserved
All other encodings are reserved.
NOTE:1. Counting data cycles is undefined for this selection.
BFN+1
50h, 58h
0
No
Description
reserved(0)
Overflow
This bit is asserted when the Event Count bit 38 carries into bit 39.
00 1000 reserved
00 1001 reserved
00 1010 reserved
00 1011 reserved
00 1100 Memory Read Multiple
00 1101 Dual Address Cycle
00 1110 Memory Read Line
00 1111 Memory Write & Invalidate
010 100 Any I/O transaction
010 101 Any I/O or memory
transactions
010 110 Any I/O or memory read
010 111 Any I/O or memory write
011 100 reserved
011 101 reserved
011 110 LOCK
011 111 ACK64
Size:
Attribute:
Locked:
Intel® 460GX Chipset Software Developer's Manual
64 bits
Read/Write
No