KS8993M Micrel Inc, KS8993M Datasheet - Page 40

• Manufacturer Part Number: KS8993M
• Description: IC SWITCH 10/100 3PORT 128PQFP
• Manufacturer: Micrel Inc

Specifications of KS8993M

• Applications: *
• Mounting Type: Surface Mount
• Package / Case: 128-MQFP, 128-PQFP
• Number Of Primary Switch Ports: 3
• Internal Memory Buffer Size: 32
• Operating Supply Voltage (typ): 1.8/2.5/3.3V
• Fiber Support: Yes
• Integrated Led Drivers: Yes
• Phy/transceiver Interface: MII/SNI
• Power Supply Type: Analog/Digital
• Package Type: PQFP
• Data Rate (typ): 10/100Mbps
• Vlan Support: Yes
• Operating Temperature (max): 70C
• Operating Temperature (min): 0C
• Pin Count: 128
• Mounting: Surface Mount
• Jtag Support: No
• Operating Supply Voltage (max): 1.89/3.465V
• Operating Supply Voltage (min): 1.71/3.135V
• Power Dissipation: 800mW
• Supply Current: 0.1/0.19A
• Operating Temperature Classification: Commercial
• Data Rate: 100Mbps
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With: 576-1013 - BOARD EVAL EXPERIMENT KS8993M
• Lead Free Status / RoHS Status: Not Compliant, Lead free / RoHS Compliant

SPI multiple read is initiated when the master device continues to drive the KS8993M SPIS_N input pin (SPI
Slave Select signal) low after a byte (a register) is read. The KS8993M internal address counter will increment
automatically to the next byte (next register) after the read. The next byte at the next register address will be
shifted out onto the KS8993M SPIQ output pin. SPI multiple read will continue until the SPI master device
terminates it by de-asserting the SPIS_N signal to the KS8993M.
Similarly, SPI multiple write is initiated when the master device continues to drive the KS8993M SPIS_N input pin
low after a byte (a register) is written. The KS8993M internal address counter will increment automatically to the
next byte (next register) after the write. The next byte that is sent from the master device to the KS8993M SDA
input pin will be written to the next register address. SPI multiple write will continue until the SPI master device
terminates it by de-asserting the SPIS_N signal to the KS8993M.
For both SPI multiple read and multiple write, the KS8993M internal address counter will wrap back to register
address zero once the highest register address is reached. This feature allows all 128 KS8993M registers to be
read, or written with a single SPI command and any initial register address.
The following is a sample procedure for programming the KS8993M using the SPI bus:
1. At the board level, connect the KS8993M pins as follows:
2. Enable SPI slave mode by setting the KS8993M strap-in pins PS[1:0] (pins 100 and 101, respectively) to “10”.
3. Power up the board and assert reset to the KS8993M.
4. Configure the desired register settings in the KS8993M, using the SPI write or multiple write command.
5. Read back and verify the register settings in the KS8993M, using the SPI read or multiple read command.
6. Write a ‘1’ to the “Start Switch” bit to start the KS8993M 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.
The following four figures illustrate the SPI data cycles for “Write”, “Read”, “Multiple Write” and “Multiple Read”.
The read data is registered out of SPIQ on the falling edge of SPIC, and the data input on SPID is registered on
the rising edge of SPIC.
The KS8993M is capable of supporting a 5MHz SPI bus.
Micrel, Inc.
April 2005
After reset, the “Start Switch” bit (register 1 bit 0) will be set to ‘0’.
KS8993M Pin #
99
97
98
96
KS8993M Signal Name
SPIS_N
SCL
(SPIC)
SDA
(SPID)
SPIQ
Table 11. KS8993M SPI Connections
40
External Processor Signal Description
SPI Slave Select
SPI Clock
SPI Data
(Master output; Slave input)
SPI Data
(Master input; Slave output)
KS8993M/ML/MI
M9999-041205