ADMCF328BRZ Analog Devices Inc, ADMCF328BRZ Datasheet - Page 21

• Manufacturer Part Number: ADMCF328BRZ
• Manufacturer: Analog Devices Inc

Specifications of ADMCF328BRZ

• Operating Current: 123mA
• Operating Temperature Classification: Industrial
• Package Type: SOIC W
• Operating Supply Voltage (min): -0.3V
• Operating Supply Voltage (max): 7V
• Lead Free Status / Rohs Status: Compliant

WATCHDOG TIMER
The ADMCF328 incorporates a watchdog timer that can per-
form a full reset of the DSP and motor control peripherals in the
event of software error. The watchdog timer is enabled by writing a
timeout value to the 16-bit WDTIMER register. The timeout
value represents the number of CLKIN cycles required for the
watchdog timer to count down to zero. When the watchdog timer
reaches zero, a full DSP core and motor control peripheral reset
is performed. In addition, Bit 1 of the SYSSTAT register is set
so that after a watchdog reset, the ADMCF328 can determine
that the reset was due to the timeout of the watchdog timer
and not an external reset. Following a watchdog reset, Bit 1 of
the SYSSTAT register may be cleared by writing zero to the
WDTIMER register. This clears the status bit but does not
enable the watchdog timer.
On reset, the watchdog timer is disabled and is only enabled
when the first timeout value is written to the WDTIMER register.
To prevent the watchdog timer from timing out, the user must
write to the WDTIMER register at regular intervals (shorter than
the programmed WDTIMER period value). On all but the first
write to WDTIMER, the particular value written to the register
is unimportant since writing to WDTIMER simply reloads the
first value written to this register.
PROGRAMMABLE DIGITAL INPUT/OUTPUT
The ADMCF328 has nine programmable digital input/output
(PIO) pins that are all multiplexed with other functions. The nine
PIO lines PIO0–PIO8 are multiplexed with the serial port (Pins
PIO0/TFS1 to PIO5/RFS1), the CLKOUT (pin PIO6/CLKOUT)
and the auxiliary PWM outputs (Pins PIO7/AUX1 and PIO8/
AUX0). When configured as a PIO, each of these nine pins can
act as an input, output, or an interrupt source.
The operating mode of pins PIO0/TFS1 to PIO7/AUX1 is con-
trolled by the PIOSELECT register. This 8-bit register has a bit
for each input so that the mode of each pin may be selected indi-
vidually. Bit 0 of PIOSELECT controls the operation of the
PIO0/TFS1 pin. Bit 1 controls the PIO1/DT1 pin, etc. Setting
the appropriate bit in the PIOSELECT register causes the cor-
responding pin to be configured for PIO functionality. Clearing
the bit selects the alternate (SPORT, CLKOUT, or AUXPWM)
mode of the corresponding pin. Following power-on reset, all
bits of PIOSELECT are set such that PIO functionality is
selected. The operating mode of the PIO8/AUX0 pin is selected
by Bit 1 of the PIODATA1 register. In a manner identical to the
PIOSELECT register, setting this bit enables PIO functionality
(PIO8) while clearing the bit enables auxiliary PWM functional-
ity (AUX0).
Once PIO functionality has been selected for any or all of these
nine pins, the direction may be set by the 8-bit PIODIR0 regis-
ter (for PIO0 to PIO7) and the 1-bit PIODIR1 register (for PIO8).
Clearing any bit configures the corresponding PIO line as an
REV. A
AUXILIARY PWM TIMERS
Parameter
Resolution
PWM Frequency
Table VIII. Fundamental Characteristics of Auxiliary PWM Timer of ADMCF328
Test Conditions
10 MHz CLKIN
–21–
input while setting the bit configures it as an output. By default,
following a reset, all bits of PIODIR0 and PIODIR1 are cleared
configuring the PIO lines as inputs.
The data of the PIO0 to PIO8 lines is controlled by the
PIODATA0 register (for PIO0 to PIO7) and Bit 0 of the
PIODATA1 register (for PIO8). These registers can be used to
read data from those PIO lines configured as inputs and write data
to those configured as outputs. Any of the nine pins that have been
configured for PIO functionality can be made to act as an interrupt
source by setting the appropriate bit of the PIOINTEN0 register
(for PIO0 to PIO7) or the PIOINTEN1 register (for PIO8). In
order to act as an interrupt source the pin must also be configured
as an input. An interrupt is generated upon a change of state
(low-to-high transition or high-to-low transition) on any input
that has been configured as an interrupt source. Following a
change of state event on any such input, the corresponding
bit is set in the PIOFLAG0 register (for PIO0 to PIO7) and
PIOFLAG1 (for PIO8) and a common PIO interrupt is gener-
ated. Reading the PIOFLAG0 and PIOFLAG1 registers permits
determining the interrupt source. Reading the PIOFLAG0 and
PIOFLAG1 registers automatically clears all bits of the registers.
Following power-on or reset, all bits of PIOINTEN0 and
PIOINTEN1 are cleared so that no interrupts are enabled.
Each PIO line has an internal pull-down resistor so that follow-
ing power-on or reset all nine lines are configured as input PIOs
and will be read as logic lows if left unconnected.
Multiplexing of PIO Lines
The PIO0–PIO5 lines are multiplexed on the ADMCF328 with
the functional lines of the serial port, SPORT1. Although the
PIOSELECT register permits individual selection of the function-
ality of each pin, certain restrictions apply when using SPORT1
for serial communications.
In general, when transmitting and receiving data on the DTI and
DRIB pins, respectively, the PIO0/TFS1 and PIO5/RFS1 pins
must also be selected for SPORT (TFS1 and RFS1) functional-
ity even if unframed communication is implemented. Therefore,
when using SPORT1 for any type of serial communication, the
minimal setting for PIOSELECT is 0xD8 (i.e., select DTI, DRIB,
RFS1 and TFS1, select PIO7, PIO6, PIO4, PIO3 as digital I/O).
If the serial port communications use an internally generated
SCLK1, the PIO3/SCLK1 pin may be used as a general-purpose
PIO line. When external SCLK mode is selected, the PIO/SCLK1
pin must be enabled as SCLK1 (PIOSELECT [3] = 0).
When the DRIB data receive line of SPORT1 is selected as
the data receive line (MODECTRL [4] = 1), the PIO4/DRIA
line may be used as a general-purpose PIO pin. When the DRIA
data receive line of SPORT1 is selected as the data receive line
(MODECTRL [4] = 0), the PIO2/DRIB line may be used as
a general-purpose PIO pin.
Min
0.039
Typ
8
Max
ADMCF328
Unit
Bits
MHz