ds96-039wdsp ETC-unknow, ds96-039wdsp Datasheet - Page 75

• Manufacturer Part Number: ds96-039wdsp
• Description: Clarification Serial Control Register Description Dsp1620/27/28/29 Devices
• Manufacturer: ETC-unknow

February 1997
6 Signal Descriptions
CKI2
Input Clock 2: Used with mask-programmable input
clock options which require an external small signal dif-
ferential across CKI and CKI2 (see Table 1, Pin De-
scriptions). When the CMOS option is selected, this pin
should be tied to V
STOP
Stop Input Clock: Negative assertion. A high-to-low
transition synchronously stops all of the internal proces-
sor clocks leaving the processor in a defined state. Re-
turning the pin high will synchronously restart the
processor clocks to continue program execution from
where it left off without any loss of state. This hardware
feature has the same effect as setting the NOCK bit in
the powerc register (see Table 43).
CKO
Clock Out: Buffered output clock with options pro-
grammable via the ioc register (see Table 42). The se-
lectable CKO options (see Tables 42 and 33) are as
follows:
Lucent Technologies Inc.
A free-running output clock at the frequency of the
internal processor clock; runs at the internal ring os-
cillator frequency when SLOWCKI is enabled.
A wait-stated clock based on the internal instruction
cycle; runs at the internal ring oscillator frequency
when SLOWCKI is enabled.
A sequenced, wait-stated clock based on the EMI
sequencer cycle; runs at the internal ring oscillator
frequency when SLOWCKI is enabled.
A free-running output clock that runs at the CKI rate,
independent of the powerc register setting. This
option is only available with the small-signal clock
options. When the PLL is selected, the CKO fre-
quency equals the input CKI frequency regardless
of how the PLL is programmed.
A logic 0.
A logic 1.
SSA
.
(continued)
INT[1:0]
Processor Interrupts 0 and 1: Positive assertion.
Hardware interrupt inputs to the DSP1628. Each is en-
abled via the inc register. When enabled and asserted,
each cause the processor to vector to the memory loca-
tion described in Table 4. INT1 is used in conjunction
with EXM to select the desired reset initialization of the
mwait register (see Table 40). When both INT0 and
RSTB are asserted, all output and bidirectional pins
(except TDO, which 3-states by JTAG control) are
put in a 3-state condition.
VEC[3:0]
Interrupt Output Vector: These four pins indicate
which interrupt is currently being serviced by the device.
Table 4 shows the code associated with each interrupt
condition. VEC[3:0] are multiplexed with IOBIT[4:7].
IACK
Interrupt Acknowledge: Positive assertion. IACK
signals when an interrupt is being serviced by the
DSP1628. IACK remains asserted while in an interrupt
service routine, and is cleared when the ireturn instruc-
tion is executed.
TRAP
Trap Signal: Positive assertion. When asserted, the
processor is put into the trap condition, which normally
causes a branch to the location 0x0046. The hardware
development system (HDS) can configure the trap pin
to cause an HDS trap, which causes a branch to loca-
tion 0x0003. Although normally an input, the pin can be
configured as an output by the HDS. As an output, the
pin can be used to signal an HDS breakpoint in a multi-
ple processor environment.
DSP1628 Digital Signal Processor
73