IDT SMBus Interfaces
PES16NT2 User Manual
6 - 8
April 15, 2008
Notes
Programming the Serial EEPROM
The serial EEPROM may be programmed prior to board assembly or in-system via the slave SMBus
interface or a PCIe® root. Programming the serial EEPROM via the slave SMBus is described in section
Serial EEPROM Read or Write Operation on page 6-12. A PCIe root may read and write the serial
EEPROM by performing configuration read and write transactions to the port A Serial EEPROM Interface
(PA_EEPROMINTF) register.
To read a byte from the serial EEPROM, the root should configure the Address (ADDR) field in the
PA_EEPROMINTF register with the byte address of the serial EEPROM location to be read and the Opera-
tion (OP) field to “read.” The Busy (BUSY) bit should then be checked. If the EEPROM is not busy, the read
operation may be initiated by performing a write to the Data (DATA) field. When the serial EEPROM read
operation completes, the Done (DONE) bit in the PA_EEPROMINTF register is set and the busy bit is
cleared. When this occurs, the DATA field contains the byte data of the value read from the serial EEPROM.
To write a byte to the serial EEPROM, the root should configure the ADDR field with the byte address of
the serial EEPROM location to be written and set the OP field to “write.” If the serial EEPROM is not busy
(i.e., the BUSY bit is cleared), the write operation may be initiated by writing the value to be written to the
DATA field. When the write operation completes, the DONE bit is set and the busy bit is cleared.
Initiating a serial EEPROM read or write operation when the BUSY bit is set produces undefined results.
SMBus errors may occur when accessing the serial EEPROM. If an error occurs, it is reported in the port A
SMBus Status (PA_SMBUSSTS) register. Software should check for errors before and after each serial
EEPROM access.
Slave SMBus Interface
The slave SMBus interface provides the PES16NT2 with a configuration, management and debug inter-
face. Using the slave SMBus interface, an external master can read or write any software visible register in
the device.
Error
Action Taken
Configuration Done Sequence checksum
mismatch with that computed by the
PES16NT2
- Set RSTHALT bit in PA_SWCTL register
- ICSERR bit is set in the PA_SMBUSSTS register
- Abort initialization, set DONE bit in the PA_SMBUSSTS register
Serial EERPOM address roll-over from
0xFFFF to 0x0000
- Set RSTHALT bit in PA_SWCTL register
- ICSERR bit is set in the PA_SMBUSSTS register
- Abort initialization, set DONE bit in the PA_SMBUSSTS register
Invalid configuration block type
(only invalid type is 0x2)
- Set RSTHALT bit in PA_SWCTL register
- ICSERR bit is set in the PA_SMBUSSTS register
- Abort initialization, set DONE bit in the PA_SMBUSSTS register
An unexpected NACK is observed during a
master SMBus transaction
- Set RSTHALT bit in PA_SWCTL register
- NAERR bit is set in the PA_SMBUSSTS register
- Abort initialization, set DONE bit in the PA_SMBUSSTS register
Master SMBus interface loses 16 consecu-
tive arbitration attempts
- Set RSTHALT bit in PA_SWCTL register
- LAERR bit is set in the PA_SMBUSSTS register
- Abort initialization, set DONE bit in the PA_SMBUSSTS register
A misplaced START or STOP condition is
detected by the master SMBus interface
- Set RSTHALT bit in PA_SWCTL register
- OTHERERR bit is set in the PA_SMBUSSTS register
- Abort initialization, set DONE bit in the PA_SMBUSSTS register
Table 6.6 Serial EEPROM Initialization Errors
Содержание 89HPES16NT2
Страница 14: ...DT List of Figures PES16NT2 User Manual viii April 15 2008 Notes...
Страница 20: ...IDT Register List PES16NT2 User Manual xiv April 15 2008 Notes...
Страница 32: ...IDT PES16NT2 Device Overview PES16NT2 User Manual 1 12 April 15 2008 Notes...
Страница 44: ...IDT Clocking Reset and Initialization Clock Operation PES16NT2 User Manual 2 12 April 15 2008 Notes...
Страница 50: ...IDT Link Operation PES16NT2 User Manual 3 6 April 15 2008 Notes...
Страница 62: ...IDT Power Management PES16NT2 User Manual 5 4 April 15 2008 Notes...
Страница 78: ...IDT SMBus Interfaces PES16NT2 User Manual 6 16 April 15 2008 Notes...
Страница 83: ...IDT NTB Upstream Port Failover PES16NT2 User Manual 7 5 April 15 2008 Notes...
Страница 84: ...IDT NTB Upstream Port Failover PES16NT2 User Manual 7 6 April 15 2008 Notes...
Страница 130: ...IDT Transparent Mode Operation PES16NT2 User Manual 9 44 April 15 2008 Notes...
Страница 284: ...IDT Non Transparent Mode Operation PES16NT2 User Manual 10 154 April 15 2008 Notes...