TMP47C990E TOSHIBA [Toshiba Semiconductor], TMP47C990E Datasheet - Page 15

• Manufacturer Part Number: TMP47C990E
• Description: CMOS 4-bit Microcontroller
• Manufacturer: TOSHIBA [Toshiba Semiconductor]

TOSHIBA CORPORATION
Note 1: In the hold operation, the dissipation of the power associated with
Note 2: In the CMOS circuitry, a current does not flow when the input level
b. Edge-sensitive release (clock) mode
In this mode, the hold operation is released at the ris-
ing edge of the HOLD pin input. This mode is used for
applications in which a relatively short-time program
processing is repeated at a certain cycle. This cyclic
signal (for example, the clock supplied from the low
power dissipation oscillator). In the edge-sensitive
the oscillator and the internal hardware is lowered; however, the
power dissipation associated with the pin interface (depending on
the external circuitry and program) is not directly determined by the
hardware operation of the hold feature. This point should be con-
sidered in the system design and the interface circuit design.
is stable at the power voltage level (V
input level gets higher than the power voltage level (by approxi-
mately 0.3 to 0.5 V), a current begins to flow. Therefore, if cutting
off the output transistor at an I/O port (the open drain output pin
with an input transistor connected) puts the pin signal into the
high-impedance state, a current flows across the ports input tran-
sistor, requiring to fix the level by pull-up or other means.
DD
Figure 2-19. Level-Sensitive Release Mode
/V
Figure 2-20. Edge-Sensitive Release Mode
SS
): however, when the
(2)
mode, even if the HOLD pin input is high, the hold
operation is performed.
Example: To start the hold operation in the edge-sen-
Releases Hold Operating Mode
The hold operating mode is released in the following
sequence:
The oscillator starts
Warm-up is performed to acquire the time for stabi-
lizing oscillation. During the warm-up, the internal
operations are all stopped. One of three warm-up
times can be selected by program depending on
the characteristics of the oscillator used.
When the warm-up time has passed, an ordinary
operation restarts from the instruction next to the
instruction which starts the hold operation. At this
time, the interval timer starts from the reset state
“0”.
LD
OUT A, %OP10
sitive release mode (the warm-up time =
2
14
A, #0101B ;
/fc).
OP10 0101
TMP47C101/201
B
15/32