
IDT SMBus Interfaces
PES32NT24xG2 User Manual
12 - 7
January 30, 2013
Notes
Figure 12.6 Example of Multiple Configuration Images in Serial EEPROM
The PES32NT24xG2 imposes no limitations on the number of jump configuration blocks that may be
executed while reading the serial EEPROM. Jump configuration blocks may be located at any byte address
within the serial EEPROM.
The fourth type of configuration block is the Wait block. The format of a Wait configuration block is
shown in
. The CFG TYPE field indicates the type of the configuration block. For Wait config-
uration blocks, this value is always 0x3.
As shown in the figure, this configuration block has fields that contain a double-word system address, a
32-bit data value, and a 32-bit mask. The wait block causes the loading of subsequent EEPROM blocks to
be suspended until the internal device register at the specified system address contains a value that
matches the 32-bit data value provided in the Wait block. The 32-bit mask register is a bit-array that dictates
which bits are compared. Bits in the 32-bit data whose corresponding mask bit is set to 1 are masked from
comparison (i.e., not compared). Unmasked bits participate in comparison.
Upon reading the Wait configuration block, the SMBus master interface stops reading subsequent
configuration blocks from the EEPROM and internally “polls” the value of the register specified SYSADDR
field in the Wait block. When the value at this internal register matches the 32-bit data value in the Wait
block (masked bits do not participate in the comparison), the SMBus master resumes EEPROM loading
and reads the next configuration block.
If the SYSADDR field in the Wait configuration block points to a register that is not defined in the global
address space (i.e., not defined in Chapter 19), then the Unmapped Register Access (URA) bit is set in the
SMBUSSTS register and EEPROM loading resumes at the instruction following the Wait configuration
block.
When executing a Wait configuration block, the maximum wait time allowed by the SMBus master can
be configured via the SMBUSCTL register. Each time a Wait configuration block is read from the EEPROM,
an internal timer is reset and activated. This internal timer is incremented each clock cycle (i.e., 250 MHz)
until the Wait block completes execution or a wait timeout occurs. If the timer reaches the value in the Wait
Configuration Block Time Out (WCBT) field in the SMBUSCTL register, a wait timeout occurs and the
following actions are taken:
–
The Wait Configuration Block Timeout (WCBTO) bit is set in the SMBUSSTS register.
–
Loading of the serial EEPROM is aborted and the RSTHALT bit is set in the SWCTL register.
Jump 1 Block
Configuration Image B
Configuration Image A
Configuration Image C
Configuration Done Block
Configuration Done Block
Configuration Done Block
Jump 0 Block
Serial EEPROM
0x0
0xFFFF
Summary of Contents for PCI Express 89HPES32NT24xG2
Page 20: ...IDT Table of Contents PES32NT24xG2 User Manual x January 30 2013 Notes...
Page 24: ...IDT List of Tables PES32NT24xG2 User Manual xiv January 30 2013 Notes...
Page 28: ...IDT List of Figures PES32NT24xG2 User Manual xviii January 30 2013 Notes...
Page 56: ...IDT PES32NT24xG2 Device Overview PES32NT24xG2 User Manual 1 20 January 30 2013 Notes...
Page 100: ...IDT Switch Core PES32NT24xG2 User Manual 4 22 January 30 2013 Notes...
Page 128: ...IDT Failover PES32NT24xG2 User Manual 6 4 January 30 2013 Notes...
Page 148: ...IDT Link Operation PES32NT24xG2 User Manual 7 20 January 30 2013 Notes...
Page 164: ...IDT SerDes PES32NT24xG2 User Manual 8 16 January 30 2013 Notes...
Page 170: ...IDT Power Management PES32NT24xG2 User Manual 9 6 January 30 2013 Notes...
Page 196: ...IDT Transparent Switch Operation PES32NT24xG2 User Manual 10 26 January 30 2013 Notes...
Page 244: ...IDT SMBus Interfaces PES32NT24xG2 User Manual 12 40 January 30 2013 Notes...
Page 247: ...IDT General Purpose I O PES32NT24xG2 User Manual 13 3 January 30 2013 Notes...
Page 248: ...IDT General Purpose I O PES32NT24xG2 User Manual 13 4 January 30 2013 Notes...
Page 330: ...IDT Switch Events PES32NT24xG2 User Manual 16 6 January 30 2013 Notes...
Page 342: ...IDT Multicast PES32NT24xG2 User Manual 17 12 January 30 2013 Notes...
Page 344: ...IDT Temperature Sensor PES32NT24xG2 User Manual 18 2 January 30 2013 Notes...
Page 384: ...IDT Register Organization PES32NT24xG2 User Manual 19 40 January 30 2013...
Page 492: ...IDT Proprietary Port Specific Registers PES32NT24xG2 User Manual 21 44 January 30 2013 Notes...
Page 588: ...IDT NT Endpoint Registers PES32NT24xG2 User Manual 22 96 January 30 2013 Notes...
Page 710: ...IDT JTAG Boundary Scan PES32NT24xG2 User Manual 25 12 January 30 2013 Notes...
Page 743: ...IDT Usage Models PES32NT24xG2 User Manual 26 33 January 30 2013 Notes...
Page 744: ...IDT Usage Models PES32NT24xG2 User Manual 26 34 January 30 2013 Notes...