High Performance Two Port 10/100 Managed Ethernet Switch with
Datasheet
Chapter 10 Serial Management
10.1Functional Overview
This chapter details the LAN9312 serial management functionality of the I2C/Microwire EEPROM Controller and the supporting EEPROM Loader.
The I2C/Microwire EEPROM controller is an I2C/Microwire master module which interfaces an optional external EEPROM with the system register bus and the EEPROM Loader. Multiple types (I2C/Microwire) and sizes of external EEPROMs are supported. Configuration of the EEPROM type and size are accomplished via the eeprom_type_strap and eeprom_size_strap[1:0] configuration straps respectively. Various commands are supported for each EEPROM type, allowing for the storage and retrieval of static data. The I2C interface conforms to the Philips
The EEPROM Loader provides the automatic loading of configuration settings from the EEPROM into the LAN9312 at reset. The EEPROM Loader module interfaces to the EEPROM Controller, Ethernet PHYs, and the system CSRs.
10.2I2C/Microwire Master EEPROM Controller
Based on the configuration strap eeprom_type_strap, the I2C/Microwire EEPROM controller supports either Microwire or I2C compatible EEPROMs. The I2C/Microwire serial management pins functionality and characteristics differ dependant on the selected EEPROM type as summarized in Table 10.1.
Table 10.1 I2C/Microwire Master Serial Management Pins Characteristics
EEPROM |
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TYPE/MODE | EE_SDA/EEDI PIN | EEDO PIN | EECS PIN | EE_SCL/EECLK PIN | |
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I2C Master | EE_SDA | NOT USED | NOT USED | EE_SCL | |
EEPROM | Input enabled | Input enabled | Input enabled | Input enabled | |
Mode | (to I2C master) | (used for straps) | (used for straps) | (to I2C master and | |
eeprom_type_strap | Output enabled | Output enabled | used for straps) | ||
= 1 | (from I2C master) | (driven low) | (driven low) | ||
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Microwire | EEDI | EEDO | EECS | EECLK | |
Master | Input enabled | Input enabled | Input enabled | Input enabled | |
EEPROM | |||||
(to Microwire master) | (used for straps) | (used for straps) | (used for straps) | ||
Mode | |||||
Output disabled | Output enabled (from | Output enabled (from | Output enabled (from | ||
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eeprom_type_strap | Microwire master) | Microwire master) | Microwire master) | ||
= 0 |
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Note: When the EEPROM Loader is running, it has exclusive use of the I2C/Microwire EEPROM controller. Refer to Section 10.2.4, "EEPROM Loader" for more information.
SMSC LAN9312 | 137 | Revision 1.4 |
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