4283 Group
(4) Return signal
An external wakeup signal is used to return from the RAM
back-up mode. Table 8 shows the return condition for each
return source.
Table 8 Return source and return condition
Return source
Ports D4–D7
Return condition
Return by an external “H” level Only key-on wakeup function of the port whose pull-down transistor is
input. turned ON by register PU1 is valid.
Return by an external “H” level Only key-on wakeup function of the port whose pull-down transistor is
input. turned ON by register PU0 is valid.
Remarks
Ports E0, E1, G
Port E2
Return by an external “H” level Key-on wakeup function is always valid.
input.
(5) Pull-down control register
Set the contents of register PU0 or PU1 through register A
with the TPU0A or TPU1A instruction, respectively.
Registers PU0 and PU1 are 4-bit registers and control the
ON/OFF of pull-down transistor and key-on wakeup function
for ports E0, E1, G and ports D4–D7.
Table 9 Pull-down control registers
Pull-down control register PU0
at reset : 00002
at RAM back-up : state retained
W
Ports G2, G3 pull-down transistor control
Pull-down transistor OFF, key-on wakeup invalid
Pull-down transistor ON, key-on wakeup valid
Pull-down transistor OFF, key-on wakeup invalid
Pull-down transistor ON, key-on wakeup valid
Pull-down transistor OFF, key-on wakeup invalid
Pull-down transistor ON, key-on wakeup valid
Pull-down transistor OFF, key-on wakeup invalid
Pull-down transistor ON, key-on wakeup valid
0
1
0
1
0
1
0
1
PU03
PU02
PU01
PU00
bit
Ports G0, G1 pull-down transistor control
bit
Port E1 pull-down transistor control bit
Port E0 pull-down transistor control bit
Pull-down control register PU1
at reset : 00002
at RAM back-up : state retained
W
Pull-down transistor OFF, key-on wakeup invalid
Pull-down transistor ON, key-on wakeup valid
Pull-down transistor OFF, key-on wakeup invalid
Pull-down transistor ON, key-on wakeup valid
Pull-down transistor OFF, key-on wakeup invalid
Pull-down transistor ON, key-on wakeup valid
Pull-down transistor OFF, key-on wakeup invalid
Pull-down transistor ON, key-on wakeup valid
0
1
0
1
0
1
0
1
PU13
PU12
PU11
PU10
Port D7 pull-down transistor control bit
Port D6 pull-down transistor control bit
Port D5 pull-down transistor control bit
Port D4 pull-down transistor control bit
Note: “W” represents write enabled.
Rev.1.01 Mar 20, 2006 page 21 of 62
REJ03B0109-0101
RENESAS [ RENESAS TECHNOLOGY CORP ]
