
Page 47
4
9
4
f
o
5
0
2
,
1
0
.
l
u
J
3
0
.
1
.
v
e
R
3
0
1
0
-
7
3
0
B
9
0
J
E
R
5. Reset
)
T
5
8
/
C
2
3
M
,
5
8
/
C
2
3
M
(
p
u
o
r
G
5
8
/
C
2
3
M
____________
Table 5.1 Pin States while RESET Pin is Held "L"
Pin States(2)
Pin Name
CNVSS=VSS
CNVSS=VCC
BYTE=VSS
BYTE=VCC
P0
Input port (high-impedance)
Inputs data (high-impedance)
P1
Input port (high-impedance)
Inputs data (high-impedance)
Input port (high-impedance)
P2, P3, P4 Input port (high-impedance)
Output addresses (indeterminate)
P50
Input port (high-impedance)
______
Outputs the WR signal ("H")(3)
P51
Input port (high-impedance)
________
Outputs the BHE signal (indeterminate)
P52
Input port (high-impedance)
_____
Outputs the RD signal ("H")(3)
P53
Input port (high-impedance)
Outputs the BCLK(3)
P54
Input port (high-impedance)
_________
Outputs the HLDA signal (Output signal depends on an input
__________
signal to the HOLD pin.)(3)
P55
Input port (high-impedance)
__________
Inputs the HOLD signal (high-impedance)
P56
Input port (high-impedance)
Outputs an "H" signal(3)
P57
Input port (high-impedance)
________
Inputs the RDY signal (high-impedance)
P6 to P15(1) Input port (high-impedance)
Input port (high-impedance)
NOTES:
1. Ports P11 to P15 are provided in the 144-pin package only.
2. The availability of pull-up resistors is indeterminate until internal supply voltage stabilizes.
3. Each port is in this state after power is on and internal supply voltage stabilizes, but in an indeterminate
state until internal supply voltage stabilizes.
5.2 Brown-Out Detection Reset (Hardware Reset 2)
Pins, the CPU and SFR are reset by using the built-in voltage detection circuit, which monitors the voltage
applied to the VCC1 pin.
When the VC26 bit in the VCR2 register is set to "1" (reset level detection circuit enabled), pins, the CPU
and SFR are reset as soon as the voltage applied to the VCC1 pin drops to Vdet3 or below.
Then, pins, the CPU and SFR are reset as soon as the voltage applied to the VCC1 pin reaches Vdet3r or
above. The microcomputer executes the program in an address determined by the reset vector.
The microcomputer executes the program after detecting Vdet3r and waiting
td(S-R) ms . The same pins and
registers are reset by the hardware reset 1 and brown-out detection reset, and are also placed in the same
reset state.
The microcomputer cannot exit stop mode by brown-out detection reset.
Figure 5.3 shows an example of brown-out detection reset operation.
NOTES:
1. Brown-out detection reset cannot be used in M32C/85T.