KSZ8995FQI Micrel Inc, KSZ8995FQI Datasheet - Page 64

• Manufacturer Part Number: KSZ8995FQI
• Description: 5 Port 10/100 Switch With PHY And Frame Buffers ( )
• Manufacturer: Micrel Inc

Specifications of KSZ8995FQI

• Number Of Primary Switch Ports: 5
• Internal Memory Buffer Size: 64
• Operating Supply Voltage (typ): 1.8/2.5/3.3V
• Fiber Support: Yes
• Integrated Led Drivers: Yes
• Phy/transceiver Interface: MII/SNI
• Data Rate (typ): 10/100Mbps
• Vlan Support: Yes
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Pin Count: 128
• Mounting: Surface Mount
• Jtag Support: No
• Operating Temperature Classification: Industrial
• Data Rate: 100Mbps
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 576-3300

Semptember 2008
Note:
To read out all the counters, the best performance over the SPI bus is (160+3) × 8 × 200 = 260ms, where there are 160 registers, 3 overhead, 8
clocks per access, at 5MHz. In the heaviest condition, the byte counter will overflow in 2 minutes. It is recommended that the software read all the
counters at least every 30 seconds. The per port MIB counters are designed as “read clear.” A per port MIB counter will be cleared after it is
accessed. All port dropped packet MIB counters are not cleared after they are accessed. The application needs to keep track of overflow and valid
conditions on these counters.
(2) MIB counter read (read port 2 rx 64 counter)
(3) MIB counter read (read port 1 tx drop packets)
Write to Register 110 with 0x1c (read MIB counter selected)
Write to Register 111 with 0x2e (trigger the read operation)
Then
Read Register 117 (counter value 31-24)
//If bit 31 = 1, there was a counter overflow
//If bit 30 = 0, restart (reread) from this register
Read Register 118 (counter value 23-16)
Read Register 119 (counter value 15-8)
Read Register 120 (counter value 7-0)
Write to Register 110 with 0x1d
Write to Register 111 with 0x00
Then
Read Register 119 (counter value 15-8)
Read Register 120 (counter value 7-0)
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