Intel 41210 - Manual (Page 10)

10 Intel® 41210 Serial to Parallel PCI Bridge Design Guide
Introduction
• Tunable inbound read prefetch algorithm for PCI MRM/MRL commands
• Local initialization via SMBus
• Secondary side initialization via Type 0 configuration cycles.
2.3 Power Management
• Support for PCI Express Active State Power Management (ASPM) L0s link state
• Support for PCI PM 1.1 compatible D0, D3hot and D3cold device power states
• Support for PME# event propagation on behalf of PCI devices
2.4 SMBus Interface
• Compatible with System Management Bus Specification, Revision 2.0
• Slave mode operation only.
• Full read/write access to all configuration registers
2.4.1 SMBus for configuration register initialization
• Support for local initialization of the configuration registers can be implemented using a
microcontroller via SMB.
Figure 1 shows this SMBus and the data transfer that occurs between
the 41210 Bridge and the microcontroller.
• Configuration Register information is stored internally in a microcontroller and the
information is transferred to the product via System Managed Bus (SMBus) protocols when
the device receives power or reset.
• The requirements of the microcontroller are as follows:
— Supports I
2
C and SMBus Protocols
— Has at least 256 Byte of internal EEprom space
— To facilitate this programming on the Customer Reference Board a Microchip part
PIC16F876A was used.
— Code space: estimated code size is ~2K words of program space and 32 words of RAM