
19.3 Functions
By using the key-on wakeup function, the STOP mode can be released at a STOP pin or at KWIm pin (m: 0 through
7). After resetting, the STOP pin is the only STOP mode release pin. To designate the KWIm pin as a STOP mode
release pin, therefore, it is necessary to configure the key-on wakeup control register (KWUCRn) (n: 0 or 1). Because
the STOP pin lacks a function for disabling inputs, it can be designated as a pin for receiving a STOP mode release
signal, irrespective of whether the key-on wakeup function is used or not.
·
Setting KWUCRn and P4PU registers
To designate a key-on wakeup pin (KWIm) as a STOP mode release pin, set KWUCRn<KWmEN> to "1".
After KWIm pin is set to "1" at KWUCRn<KWmEN>, a specific STOP mode release level can be specified
for this pin at KWUCRn<KWmLE>. If KWUCRn<KWmLE> is set to "0", STOP mode is released when an
input is at a low level. If it is set to "1", STOP mode is released when an input is at a high level. For example,
if you want to release STOP mode by inputting a high-level signal into a KWI0 pin, set KWUCR0<KW0EN>
to "1", " and KWUCR0<KW0LE> to "1".
Each KWIm pin can be connected to internal pull-up resistors. Before connecting to internal pull-up re-
sistors, the corresponding bits in the pull-up control register (P4PU) at port P4 must be set to "1".
·
Starting STOP mode
To start the STOP mode, set SYSCR1<RELM> to "1" (level release mode), and SYSCR1<STOP> to "1".
To use the key-on wakeup function, do not set SYSCR1<RELM> to "0" (edge release mode). If the key-
on wakeup function is used in edge release mode, STOP mode cannot be released, although a rising edge is
input into the STOP pin. This is because the KWIm pin enabling inputs to be received is at a release level
after the STOP mode starts.
·
Releasing STOP mode
To release STOP mode, input a high-level signal into the STOP pin or input a specific release level into
the KWIm pin for which receipt of inputs is enabled. If you want to release STOP mode at the KWIm pin,
rather than the STOP pin, continue inputting a low-level signal into the STOP pin throughout the period from
when the STOP mode is started to when it is released.
If the STOP pin or KWIm pin is already at a release level when the STOP mode starts, the following
instruction will be executed without starting the STOP mode (with no warm-up performed).
Note 1: If an analog voltage is applied to KWIm pin for which receipt of inputs is enabled by the key-on wakeup control
register (KWUCRn) setting, a penetration current will flow. Therefore, in this case, the analog voltage should be
not applied to this pin.
Table 19-1 STOP Mode Release Level (edge)
Pin name
Release level (edge)
SYSCR1<RELM>="1"
(level release mode)
SYSCR1<RELM>="0"
(edge release mode)
KWUCRn<KWmLE>="0"
KWUCRn<KWmLE>="1"
STOP
"H" level
Rising edge
KWIm
"L" level
"H" level
Don't use
TMP89FM42
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