MC33389DDW Freescale, MC33389DDW Datasheet - Page 30

• Manufacturer Part Number: MC33389DDW
• Manufacturer: Freescale

Specifications of MC33389DDW

• Number Of Transceivers: 1
• Power Down Mode: Sleep/Standby
• Operating Supply Voltage (max): 27V
• Operating Supply Voltage (typ): 9/12/15/18/24V
• Operating Supply Voltage (min): 5.5V
• Package Type: SOIC W
• Supply Current: 7mA
• Operating Temperature (max): 125C
• Operating Temperature (min): -40C
• Operating Temperature Classification: Automotive
• Mounting: Surface Mount
• Pin Count: 28
• Lead Free Status / RoHS Status: Not Compliant

SPI Introduction
with numerous standard peripherals and MCUs available
from Motorola and other semiconductor manufacturers. SPI
reduces the number of pins necessary for input/output on the
33389. The SPI system of communication consists of the
MCU transmitting, and in return, receiving one data bit of
information per clock cycle. Data bits of information are
simultaneously transmitted by one pin, Microcontroller Out
Serial In (MOSI), and received by another pin, Microcontroller
In Serial Out (MISO), of the MCU.
basic SPI configuration between an MCU and one 33389.
The SPI serial operation is guaranteed to 2.0 MHz.
CS PIN
communicated with, through the use of the CS pin. Whenever
the pin is in logic low state, data can be transferred from the
30
33389
FUNCTIONAL DEVICE OPERATION
LOGIC COMMANDS AND REGISTERS
This SPI system is flexible enough to communicate directly
The system MCU selects the MC33389 to be
Figure 16. SPI Interface with Microcontroller
MC68HCXX
MOSI
MISO
SCLK
CS
140
120
100
160
180
80
60
40
MOSI
MISO
Figure 16
-50
Figure 15. Current vs Temp and Batt Voltage
LOGIC COMMANDS AND REGISTERS
-25
illustrates the
33389
0
TEMPERATURE (°C)
25
50
MCU to the MC33389 and vice versa. Clocked-in data from
the MCU is transferred from the MC33389 shift register and
latched into the addressed registers on the rising edge of the
CS signal if the read/write bit is set and the parity check was
successful.
pin. Whenever the CS pin goes to a logic low state, the MISO
pin output driver is enabled allowing information to be
transferred from the MC33389 to the MCU. To avoid any
spurious data, it is essential that the high-to-low transition of
the CS signal occur only when SCLK is in a logic low state.
SCLK PIN
registers of the MC33389. The serial input pin (MOSI)
accepts data into the input shift register on the falling edge of
the SCLK signal while the serial output pin (MISO) shifts data
information out of the shift register on the rising edge of the
SCLK signal. False clocking of the shift register must be
avoided to guarantee validity of data. It is essential that the
SCLK pin be in a logic low state whenever chip select bar pin
(CS) makes any transition. For this reason, it is
recommended though not necessary, that the SCLK pin be
kept in a low logic state as long as the device is not accessed
(CS in logic high state). When CS is in a logic high state, any
signal at the SCLK and MOSI pin is ignored and MISO is
tristated (high impedance).
MOSI PIN
information is read in on the falling edge of SCLK. To
program the MC33389 by setting appropriate programming
registers, an sixteen bit serial stream of data is required to be
75
The CS pin controls the output driver of the serial output
The system clock pin (SCLK) clocks the internal shift
This pin is for the input of serial instruction data. MOSI
100
125
16 V
12 V
6.0V
150
Analog Integrated Circuit Device Data
Freescale Semiconductor