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TLC32040C, TLC32040I, TLC32041C, TLC32041I
ANALOG INTERFACE CIRCUITS
SLAS014E – SEPTEMBER 1987 – REVISED MAY 1995
4
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
Terminal Functions (continued)
TERMINAL
I/O
DESCRIPTION
NAME
NO.
11
EODX
O
End of data transmit. See the WORD/BYTE description and the Serial Port Timing diagram. During the
word-mode timing, EODX is a low-going pulse that occurs immediately after the 16 bits of D/A converter
and control or register information have been transmitted from the TMS320 serial port to the AIC. EODX
can be used to interrupt a microprocessor upon the completion of serial communications. Also, EODX can
be used to strobe and enable external serial-to-parallel shift registers, latches, or an external FIFO RAM,
and to facilitate parallel data-bus communications between the AIC and the serial-to-parallel shift registers.
During the byte-mode timing, EODX goes low after the first byte has been transmitted from the TMS320
serial port to the AIC and is kept low until the second byte has been transmitted. The TMS32011 or
TMS320C17 can use this low-going signal to differentiate between the two bytes as to which is first and
which is second.
Frame sync receive. In the serial transmission modes, which are described in the WORD/BYTE description,
FSR is held low during bit transmission. When FSR goes low, the TMS320 serial port begins receiving bits
from the AIC via DR of the AIC. The most significant DR bit is present on DR before FSR goes low. (See
Serial Port Timing and Internal Timing Configuration diagrams.) FSR does not occur after secondary
communication.
Frame sync transmit. When FSX goes low, the TMS320 serial port begins transmitting bits to the AIC via
DX of the AIC. In all serial transmission modes, which are described in the WORD/BYTE description, FSX
is held low during bit transmission (see the Serial Port Timing and Internal Timing Configuration diagrams).
FSR
4
O
FSX
14
O
IN+
26
I
Noninverting input to analog input amplifier stage
IN–
25
I
Inverting input to analog input amplifier stage
MSTR CLK
6
I
Master clock. MSTR CLK is used to derive all the key logic signals of the AIC, such as the shift clock, the
switched-capacitor filter clocks, and the A/D and D/A timing signals. The Internal Timing Configuration
diagram shows how these key signals are derived. The frequencies of these key signals are synchronous
submultiples of the master clock frequency to eliminate unwanted aliasing when the sampled analog signals
are transferred between the switched-capacitor filters and the A/D and D/A converters (see the Internal
Timing Configuration).
OUT+
22
O
Noninverting output of analog output power amplifier. OUT+ can drive transformer hybrids or
high-impedance loads directly in either a differential or a single-ended configuration.
OUT–
21
O
Inverting output of analog output power amplifier. OUT– is functionally identical with and complementary
to OUT+.
REF
8
I/O
Internal voltage reference for the TLC32040. For the TLC32040 and TLC32041 an external voltage
reference can be applied to this terminal.
RESET
2
I
Reset. A reset function is provided to initialize the TA, TA’, TB, RA, RA’, RB, and control registers. This reset
function initiates serial communications between the AIC and DSP. The reset function initializes all AIC
registers including the control register. After a negative-going pulse on RESET, the AIC registers are
initialized to provide an 8-kHz data conversion rate for a 5.184-MHz master clock input signal. The
conversion rate adjust registers, TA’ and RA’, are reset to 1. The control register bits are reset as follows
(see AIC DX data word format section):
d7 = 1, d6 = 1, d5 = 1, d4 = 0, d3 = 0, d2 = 1
This initialization allows normal serial-port communication to occur between AIC and DSP.
SHIFT CLK
10
O
Shift clock. SHIFT CLK is obtained by dividing the master clock signal frequency by four. SHIFT CLK is used
to clock the serial data transfers of the AIC, described in the WORD/BYTE description below (see the Serial
Port Timing and Internal Timing Configuration diagrams).
VDD
VCC+
VCC–
7
Digital supply voltage, 5 V
±
5%
Positive analog supply voltage, 5 V
±
5%
Negative analog supply voltage, –5 V
±
5%
20
19