
Micrel, Inc.
KSZ8864RMN
April 2012
14
M9999-043012-1.5
Pin Description (Continued)
Pin Number
Pin Name
Type
(1)
Port
Pin Function
(2)
52
P1LED0
IPU/O
1
LED indicator for Port 1.
Strap option: for Switch MAC4 only.
PU (default) = Select MII interface for the Switch MAC4 SW4-MII.
PD = Select RMII interface for the Switch MAC4 SW4-RMII.
53
MDC
IPU
All
MII management interface clock. Or SMI interface clock
54
MDIO
IPU/O
All
MII management data I/O. Or SMI interface data I/O
Features internal pull down to define pin state when not driven.
Note: Need an external pull-up when driven.
55
SPIQ
IPU/O
All
SPI serial data output in SPI slave mode.
Note: Need an external pull-up when driven.
56
SPIC/SCL
IPU/O
All
(1) Input clock up to 25MHz in SPI slave mode,
(2) output clock at 61KHz in I
2C master mode.
Note: Need an external pull-up when driven.
57
SPID/SDA
IPU/O
All
(1) Serial data input in SPI slave mode;
(2) serial data input/output in I
2C master mode.
Note: Need an external pull-up when driven.
58
SPIS_N
IPU
All
Active low.
(1) SPI data transfer start in SPI slave mode. When SPIS_N is high, the device is
deselected and SPIQ is held in high impedance state, a high-to-low transition to
initiate the SPI data transfer.
(2) Not used in I
2C master mode.
Serial bus configuration pin.
For this case, if the EEPROM is not present, the Switch will start itself with the
PS[1.0] = 00 default register values.
Pin Configuration
Serial Bus Configuration
PS[1.0]=00
I
2C Master Mode for EEPROM
PS[1.0]=01
SMI Interface Mode
PS[1.0]=10
SPI Slave Mode for CPU Interface
59
PS1
IPD
PS[1.0]=11
Factory Test Mode (BIST)
60
PS0
IPD
Serial bus configuration pin.