KSZ8893-MQL Micrel Semiconductor, Inc., KSZ8893-MQL Datasheet - Page 44

• Manufacturer Part Number: KSZ8893-MQL
• Description: Integrated 3-Port 10/100 Managed Switch with PHYs
• Manufacturer: Micrel Semiconductor, Inc.

I
In managed mode, the KSZ8893MQL can be configured as an I
device (external controller/CPU) has complete programming access to the KSZ8893MQL’s 142 registers.
Programming access includes the Global Registers, Port Registers, Advanced Control Registers and indirect
access to the “Static MAC Table”, “VLAN Table”, “Dynamic MAC Table,” and “MIB Counters.” The tables and
counters are indirectly accessed via registers 121 to 131.
In I
registers is similar to addressing Atmel’s AT24C02 EEPROM’s memory locations. Details of I
operations and related timing information can be found in the AT24C02 Datasheet.
Two fixed 8-bit device addresses are used to address the KSZ8893MQL in I
other is for write. The addresses are as follow:
The following is a sample procedure for programming the KSZ8893MQL using the I
1. Enable I
2. Power up the board and assert reset to the KSZ8893MQL. After reset, the “Start Switch” bit (register 1 bit [0])
3. Configure the desired register settings in the KSZ8893MQL, using the I
4. Read back and verify the register settings in the KSZ8893MQL, using the I
5. Write a ‘1’ to the “Start Switch” bit to start the KSZ8893MQL with the programmed settings.
Note: The “Start Switch” bit cannot be set to ‘0’ to stop the switch after an ‘1’ is written to this bit. Thus, it is
recommended that all switch configuration settings are programmed before the “Start Switch” bit is set to ‘1’.
Some of the configuration settings, such as “Aging enable”, “Auto Negotiation Enable”, “Force Speed” and “Power
down” can be programmed after the switch has been started.
SPI Slave Serial Bus Configuration
In managed mode, the KSZ8893MQL can be configured as a SPI slave device. In this mode, a SPI master device
(external controller/CPU) has complete programming access to the KSZ8893MQL’s 142 registers. Programming
access includes the Global Registers, Port Registers, Advanced Control Registers and indirect access to the
“Static MAC Table”, “VLAN Table”, “Dynamic MAC Table” and “MIB Counters”. The tables and counters are
indirectly accessed via registers 121 to 131.
The KSZ8893MQL supports two standard SPI commands: ‘0000_0011’ for data read and ‘0000_0010’ for data
write. SPI multiple read and multiple write are also supported by the KSZ8893MQL to expedite register read back
and register configuration, respectively.
SPI multiple read is initiated when the master device continues to drive the KSZ8893MQL SPIS_N input pin (SPI
Slave Select signal) low after a byte (a register) is read. The KSZ8893MQL internal address counter increments
automatically to the next byte (next register) after the read. The next byte at the next register address is shifted
out onto the KSZ8893MQL SPIQ output pin. SPI multiple read continues until the SPI master device terminates it
by de-asserting the SPIS_N signal to the KSZ8893MQL.
Similarly, SPI multiple write is initiated when the master device continues to drive the KSZ8893MQL SPIS_N input
pin low after a byte (a register) is written. The KSZ8893MQL internal address counter increments automatically to
the next byte (next register) after the write. The next byte that is sent from the master device to the KSZ8893MQL
SDA input pin is written to the next register address. SPI multiple write continues until the SPI master device
terminates it by de-asserting the SPIS_N signal to the KSZ8893MQL.
For both SPI multiple read and multiple write, the KSZ8893MQL internal address counter wraps back to register
address zero once the highest register address is reached. This feature allows all 142 KSZ8893MQL registers to
be read, or written with a single SPI command from any initial register address.
The KSZ8893MQL is capable of supporting a 5MHz SPI bus.
2
Micrel
November 2005
C Slave Serial Bus Configuration
2
C slave mode, the KSZ8893MQL operates like other I
“01”.
is set to ‘0’.
2
C slave mode by setting the KSZ8893MQL strap-in pins PS[1:0] (pins 100 and 101, respectively) to
1011_1111 <read>
1011_1110 <write>
44
2
C slave devices. Addressing the KSZ8893MQL’s 8-bit
2
C slave device. In this mode, an I
2
C write operation.
2
C slave mode. One is for read; the
2
C read operation.
2
C slave serial bus:
KSZ8893MQL/MQLI
M9999-111705
2
C read/write
2
C master