SLLSEF8C August 2013 – November 2014 TLK111
The TLK111 includes an internal power-on-reset (POR) function, and therefore does not need an explicit reset for normal operation after power up.
At power-up, if required by the system, the RESET pin (active low) should be de-asserted 200µs after the power is ramped up to allow the internal circuits to settle and for the internal regulators to stabilize. If required during normal operation, the device can be reset by a hardware or software reset.
A hardware reset is accomplished by applying a low pulse (TTL level), with a duration of at least 1μs, to RESET. This pulse resets the device such that all registers are reinitialized to default values, and the hardware configuration values are re-latched into the device (similar to the power-up/reset operation). The time from the point when the reset pin is de-asserted to the point when the reset has concluded internally is approximately 200µs.
An IEEE registers software reset is accomplished by setting the reset bit (bit 15) of the BMCR register (0x0000h). This bit only resets the IEEE-defined standard registers in the address space 0x00h to 0x07h.
A global software reset is accomplished by setting bit 15 of register PHYRCR (0x001F) to ‘1’. This bit resets all the internal circuits in the PHY including IEEE-defined registers (0x00h to 0x07h) and all the extended registers. The global software reset resets the device such that all registers are reset to default values and the hardware configuration values are maintained.
A global software restart is accomplished by setting bit 14 of register PHYRCR (0x001F) to ‘1’. This action resets all the PHY circuits except the registers in the Register File.
The time from the point when the resets/restart bits are set to the point when the software resets/restart has concluded is approximately 200µs. TI recommends that the software driver code must wait 500µs following software reset before allowing further serial MII operations with the TLK111.
The Power Down and Interrupt functions are multiplexed on pin 7 of the device. By default, this pin functions as a power down input and the interrupt function is disabled. This pin can be configured as an interrupt output pin by setting bit 0 (INT_OE) to ‘1’ in the PHYSCR (0x0011h) register. The PHYSCR register is also used to enable and set the polarity of the interrupt.
The INT/PWDN pin can be asserted low to put the device in a Power Down mode. An external control signal can be used to drive the pin low, overcoming the weak internal pull-up resistor. Alternatively, the device can be configured to initialize into a Power Down state by use of an external pulldown resistor on the INT/PWDN pin.
The interrupt function is controlled via register access. All interrupt sources are disabled by default. The MISR1 (0x0012) and MISR2 (0x0013) registers provide independent interrupt enable bits for the various interrupts supported by the TLK111. The INT/PWDN pin is asynchronously asserted low when an interrupt condition occurs. The source of the interrupt can be determined by reading the interrupt status registers MISR1 (0x0012h) and MISR2 (0x0013). One or more bits in the MISR registers will be set, indicating all currently-pending interrupts. Reading the MISR registers clears ALL pending interrupts.
The TLK111 supports three types of power-save modes. The lowest power consumption is achieved in IEEE power down mode. To enter IEEE power down mode, pull the INT/PWDN pin to LOW or program bit 11 in the Basic Mode Control Register (BMCR), address 0x0000. In this mode all internal circuitry except SMI functionality is shut down (Register access is still available).
To enable and activate all other power save modes through register access, use register PHYSCR (0x0011h). Setting bit 14 enables all power-save modes; bits [13:12] select between them.
Setting bits [13:12] to “01” powers down the PHY, forcing it into IEEE power down mode (Similar to BMCR bit 11 functionality).
When these bits are cleared, the PHY powers up and returns to the last state it was in before it was powered down.