REV. B
ADMC401
–44–
ROM or E
2PROM. Clearing the UARTEN bit selects SPORT
mode, so that SPORT1 is configured in a manner identical to
the standard serial ports of the ADSP-21xx family. Following
reset, the UARTEN bit is cleared so that SPORT mode is selected.
Bit 6 of the MODECTRL register is used to select between
single update and double update operating modes of the PWM
generation unit. Clearing this bit selects single update mode,
while setting it selects double update mode. Following reset,
this bit is cleared so that single update mode is the default
configuration.
Bit 8 of the MODECTRL register is used to select between
independent and offset operating modes of the auxiliary PWM
unit. Clearing this bit selects offset mode, while setting it selects
independent mode. Following reset, this bit is cleared so that
offset mode is the default configuration.
SYSSTAT REGISTER
The SYSSTAT register provides various status information of
the ADMC401, such as the state of the
PWMTRIP pin, the
state of the watchdog flag, the state of the PWMPOL pin and
phase of the PWM
Bit 0 indicates the state of the
PWMTRIP pin such that the bit
is set if
PWMTRIP is HI and cleared if the pin is LO. Similarly,
Bit 2 indicates the state of the PWMPOL pin such that the bit is
set if PWMPOL is HI (active high PWM selected) and cleared if
the pin is LO (active low PWM selected).
Bit 1 is used to indicate if a watchdog timer timeout has oc-
curred. This bit is set following a watchdog timeout and can be
read on reset to determine if the reset is a normal power-on
reset or due to a watchdog trip.
Bit 3 of the SYSSTAT register is used to identify the half cycle
of operation of the PWM generation unit. During the first half
cycle, when the internal PWM timer is decrementing, this bit is
cleared. During the second half cycle, this bit is set while the
timer is incrementing.
SYSTEM CONTROL REGISTERS
The configuration of the MODECTRL and SYSSTAT register
is shown at the end of the data sheet.
PERIPHERAL AND DSP CORE REGISTERS
The address, name, type, used bits and reset value of all of the
peripheral registers of the ADMC401 are given in Table VIII.
Similarly, the DSP core registers of the ADMC401 are tabu-
lated in Table IX.