MSP53C691 Datasheet, PDF (6/14 Pages) Texas Instruments – MIXED-SIGNAL PROCESSOR

MSP53C691
MIXED-SIGNAL PROCESSOR
SPSS030A – DECEMBER 2000 – REVISED FEBRUARY 2001
VDD
Master
100 kΩ
(each)
4.7 kΩ
DATA (0–7)
8
VDD
4.7 kΩ
4.7 kΩ
MSP53C691
INRDY
OUTRDY
R/W
STROBE
DATA (0–7)
RESET
NOTE: STROBE:
R/W:
RESET
INRDY:
OUTRDY:
DATA0–DATA7
PD4–PD7
DACP
DACM
Active low strobe signal from microcontroller
Read/write signal from microcontroller
Active low reset signal from microcontroller.
Active low indicates that the MSP53C691 is ready to accept data.
Active low indicates that the MSP53C691 is ready to send data.
Data bits 0 through 7
General-purpose I/O bus
Output to speaker/amplifier
Output to speaker/amplifier
Figure 2. MSP53C691 Interfacing Diagram—8-Bit Mode
read operation by the master
The process for the read operation by the master is the same in either 4-bit or 8-bit mode. The read operation
by the master happens when the slave wants to send something to the master. The read process is initiated
by the slave by pulling OUTRDY low when it is ready.
The following events take place during the read operation:
D The MSP53C691 puts the data to be sent to the master on the internal bus.
D The MSP53C691 sets OUTRDY low to indicate that it is ready to send data to the microcontroller.
D The microcontroller sets R/W high to indicate a read operation.
D The microcontroller sets STROBE low. The data is available on the external data-bus at this point.
D The microcontroller reads the data from the bus.
D The microcontroller sets STROBE high. The MSP53C691 also pulls OUTRDY high at the rising edge of
STROBE.
D The data is taken from the external data-bus after STROBE goes high.
The microcontroller should latch or read in the data while STROBE is low. When the microcontroller sets
STROBE high, the MSP53C691 sets OUTRDY high to indicate that the data has been successfully transferred.
Figure 3 shows the sequence of events of the read operation.
6
• POST OFFICE BOX 655303 DALLAS, TEXAS 75265