Multichannel Serial Interfaces
9-38
9.5.1.6
Interface Activation
Start Sequence
A typical sequence to start the interface is:
1) MCSI configuration:
a) DSP_WRITE(0x0000)= CONTROL_REG in order to remove the write
protection on the control registers
b) DSP_WRITE(0x
…
.)= MAIN_PARAMETERS_REG
c)
DSP_WRITE(0x
…
.)= INTERRUPTS_REG
d) DSP_WRITE(0x
…
.)= CHANNEL_USED_REG
e) DSP_WRITE(0x
…
.)= CLOCK_FREQUENCY_REG
f)
DSP_WRITE(0x
…
.)= OVER_CLOCK_REG
2) Transmit data loading for selected channels:
a) DSP_WRITE(0x
…
.)= TX_REG[channel index]
3) Enable MCSI clock:
a) DSP_WRITE(0x0001)= CONTROL_REG
Stop Sequence
A typical sequence to stop the interface is:
1) Disable MCSI clock: DSP_WRITE(0x0000) = CONTROL_REG
The status register keeps its content even after the stop of the
transmission. The control registers can now be modified.
2) Software reset: DSP_WRITE(0x0002) = CONTROL_REG
The software reset initializes the status register.
Software Reset
The MCSI software reset is activated with the SW_RESET bit of the control
register (CONTROL_REG) (see Table 9–34, Activity Control Register).
This reset is limited to the control and status registers, the internal state
machine, and the PISO and SIPO logic. The parameters registers are not
affected by this software reset.
On the software reset, the MCSI reference clock is disabled, thus halting the
execution of any current operating mode.