Datasheet

TMC8460-BI Datasheet (V1.00 / 2016-Sep-01)
Copyright © 2016 TRINAMIC Motion Control GmbH & Co. KG 148
6.13 MFCIO Emergency Switch Input
The TMC8460-BI comes with an additional emergency switch input pin. This input pin connects to the
MFCIO block. Its function is to indicate an error condition and to switch certain outputs of the MFCIO
block into configurable safe states.
The emergency switch input is called MFC_nES. It is low active.
MFC_nES input has impact on the following functional units and outputs:
• PWM high side and low side gate outputs are set to a defined configurable safe off state.
• All GPIO ports that are configured as outputs are set to a defined configurable safe off state.
• SD step output and internal step counter freeze
• The MFCIO_IRQ signal will be triggered
6.13.1 Activation & Usage
To activate the emergency switch input masked bit 15 in the IRQ_CFG register.
Otherwise, MFC_nES is ignored.
A microcontroller or another circuit must actively drive high VCCIO level (3.3V) at the MFC_nES input for
normal operation.
IRQ_CFG[15] = 0  MFC_nES not active, input level is ignored
IRQ_CFG[15] = 1  MFC_nES is active, must actively be driven high for normal operation
MFC_nES is triggered by setting it to low level (0V, GND) resulting in the following actions:
- IRQ_FLAGS[15] is set
- External signal/pin MFC_IRQ is set / driven high
- All output signals of the MFCIO block take their configured safe values, the S/D unit is freezed
6.13.2 Re-Activation
The internal emergency switch flag IRQ_FLAGS[158] remains set even when the pin MFC_nES is already
driven high again.
The emergency flag can only be unset be either doing a complete chip reset, by power cycling, or by
actively writing 2 times into the IRQ_CFG register at bit position 15:
First write operation: IRQ_CFG[15] = 0
Second write operation: IRQ_CFG[15] = 1
This way, the internal emergency flag is unset.
This can be done by the ECAT master or by the local application controller.
6.14 Auxiliary Clock Output
The TMC8460 provides a dedicated clock output to supply a 16MHz clock source to peripheral
components. The 16MHz clock is internally derived from the PLL logic which itself uses the 25MHz
clock input at pin CLK_25MHz as base clock.
If not required the clock can be switched off using an enable pin.
Table 155 : TMC8460 auxiliary clock pins
PKG.
Pin
Pin Name / Function
DI
R
Functional Description / Comments
U12
CLK_16MHz_OUT O 16MHz auxiliary clock output, enabled by EN_16MHz_OUT
R12
EN_16MHz_OUT I
Enable signal for 16 MHz auxiliary clock output:
0 = off
1 = on, 16 MHz available at CLK_16MHz_OUT