TMS320VC549 Datasheet, PDF (8/60 Pages) Texas Instruments – FIXED-POINT DIGITAL SIGNAL PROCESSOR

TMS320VC549
FIXEDĆPOINT DIGITAL SIGNAL PROCESSOR
SPRS078F – SEPTEMBER 1998 – REVISED MAY 2000
’549 Signal Descriptions (Continued)
TERMINAL
NAME
TYPE†
DESCRIPTION
MEMORY CONTROL SIGNALS (CONTINUED)
IAQ
O/Z
Instruction acquisition signal. IAQ is asserted (active low) when there is an instruction address on the address
bus and goes into the high-impedance state when EMU1/OFF is low.
OSCILLATOR/TIMER SIGNALS
CLKOUT
Master clock output signal. CLKOUT cycles at the machine-cycle rate of the CPU. The internal machine cycle
O/Z
is bounded by the falling edges of this signal. CLKOUT also goes into the high-impedance state when EMU1/OFF
is low.
CLKMD1
CLKMD2
CLKMD3
Clock mode external/internal input signals. CLKMD1, CLKMD2, and CLKMD3 allow you to select and configure
I
different clock modes, such as crystal, external clock, and various PLL factors. Refer to PLL section for a detailed
functional description of these pins.
X2/CLKIN
Input pin to internal oscillator from the crystal. If the internal (crystal) oscillator is not being used, a clock can
I
become input to the device using this pin. The internal machine cycle time is determined by the clock
operating-mode pins (CLKMD1, CLKMD2 and CLKMD3).
X1
O
Output pin from the internal oscillator for the crystal. If the internal oscillator is not used, X1 should be left
unconnected. X1 does not go into the high-impedance state when EMU1/OFF is low.
TOUT
O/Z
Timer output. TOUT signals a pulse when the on-chip timer counts down past zero. The pulse is a CLKOUT-cycle
wide. TOUT also goes into the high-impedance state when EMU1/OFF is low.
BUFFERED SERIAL PORT 0 AND BUFFERED SERIAL PORT 1 SIGNALS
BCLKR0
BCLKR1
Receive clocks. External clock signal for clocking data from the data-receive (DR) pin into the buffered serial port
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receive shift registers (RSRs). Must be present during buffered serial port transfers. If the buffered serial port is
not being used, BCLKR0 and BCLKR1 can be sampled as an input by way of IN0 bit of the SPC register.
BCLKX0
BCLKX1
I/O/Z
Transmit clock. Clock signal for clocking data from the serial port transmit shift register (XSR) to the data transmit
(DX) pin. BCLKX can be an input if MCM in the serial port control register is cleared to 0. It also can be driven
by the device at 1/(CLKDV + 1) where CLKDV range is 0–31 CLKOUT frequency when MCM is set to 1. If the
buffered serial port is not used, BCLKX can be sampled as an input by way of IN1 of the SPC register. BCLKX0
and BCLKX1 go into the high-impedance state when OFF is low.
BDR0
BDR1
I
Buffered serial-data-receive input. Serial data is received in the RSR by BDR0/BDR1.
BDX0
BDX1
O/Z
Buffered serial-port-transmit output. Serial data is transmitted from the XSR by way of BDX. BDX0 and BDX1 are
placed in the high-impedance state when not transmitting and when EMU1/OFF is low.
BFSR0
BFSR1
I
Frame synchronization pulse for receive input. The falling edge of the BFSR pulse initiates the data-receive
process, beginning the clocking of the RSR.
BFSX0
BFSX1
I/O/Z
Frame synchronization pulse for transmit input/output. The falling edge of the BFSX pulse initiates the
data-transmit process, beginning the clocking of the XSR. Following reset, the default operating condition of
BFSX is an input. BFSX0 and BFSX1 can be selected by software to be an output when TXM in the serial control
register is set to 1. This pin goes into the high-impedance state when EMU1/OFF is low.
SERIAL PORT 0 AND SERIAL PORT 1 SIGNALS
CLKR0
CLKR1
Receive clocks. External clock signal for clocking data from the data receive (DR) pin into the serial port receive
I
shift register (RSR). Must be present during serial port transfers. If the serial port is not being used, CLKR0 and
CLKR1 can be sampled as an input via IN0 bit of the SPC register.
CLKX0
CLKX1
I/O/Z
Transmit clock. Clock signal for clocking data from the serial port transmit shift register (XSR) to the data transmit
(DX) pin. CLKX can be an input if MCM in the serial port control register is cleared to 0. It also can be driven by
the device at 1/4 CLKOUT frequency when MCM is set to 1. If the serial port is not used, CLKX can be sampled
as an input via IN1 of the SPC register. CLKX0 and CLKX1 go into the high-impedance state when EMU1/OFF
is low.
DR0
DR1
I
Serial-data-receive input. Serial data is received in the RSR by DR.
† _{I = Input, O = Output, Z = High impedance}
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