RESET
3.3 State of internal area
Register name
Address
Access characteristics
State immediately after reset
b7
b0
b7
b0
(Note 8)
? (Note 9)
60 16
Watchdog timer register
61 16
62 16
63 16
64 16
65 16
66 16
67 16
68 16
69 16
6A16
6B16
6C16
6D16
6E16
6F16
70 16
71 16
Watchdog timer frequency select register
Particular function select register 0
0
0
0
0
0
0
?
0
0
0
0
RW RW
RW
RW
RW (Note 10)
RW
RWRW RW
0
0
0
0
0
0
0
Particular function select register 1
Particular function select register 2
(Note 11)
(Note 12)
?
?
(Note 13)
(Note 12)
(Note 12)
Debug control register 0
Debug control register 1
RW
0
?
0
0
1
0
0
0
0
0
RO RO
RW RW RO RW
0
0
RW (Note 14)
?
?
Address comparison register 0
Address comparison register 1
RW (Note 14)
RW (Note 14)
RW (Note 14)
RW (Note 14)
RW (Note 14)
?
?
?
?
?
?
0
0
0
0
0
0
?
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
INT
3
4
interrupt control register
interrupt control register
RW
RW
INT
?
A-D conversion interrupt control register
UART0 transmit interrupt control register
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
?
?
?
?
?
?
72 16 UART0 receive interrupt control register
73 16 UART1 transmit interrupt control register
74 16
UART1 receive interrupt control register
75 16
76 16
77 16
78 16
Timer A0 interrupt control register
Timer A1 interrupt control register
Timer A2 interrupt control register
Timer A3 interrupt control register
?
?
?
?
?
?
79 16 Timer A4 interrupt control register
7A16
7B16
7C16
7D16
7E16
7F16
Timer B0 interrupt control register
Timer B1 interrupt control register
Timer B2 interrupt control register
(Note 13)
(Note 13)
(Note 13)
?
?
?
Notes 8 : By writing dummy data to address 6016, a value of “FFF16” is set to the watchdog timer.
The dummy data is not retained anywhere.
9 : A value of “FFF16” is set to the watchdog timer. (Refer to “CHAPTER 14. WATCHDOG TIMER.”)
10 : After writing “5516” to address 6216, each bit must be set.
11 : It is possible to read the bit state at reading. By writing “0” to this bit, this bit becomes “0.”
But when writing “1” to this bit, this bit will not change.
12 : This bit becomes “0” at power-on reset. This bit retains the state immediately before reset in the case of
hardware reset and software reset.
13 : Do not write.
14 : When these registers are accessed, set the address comparison register access enable bit (bit 2 at address
6716) to “1.” (Refer to “CHAPTER 17. DEBUG FUNCTION.”)
Fig. 3.3.5 State of SFR and internal RAM areas immediately after reset (4)
7906 Group User’s Manual Rev.2.0
3-10
RENESAS [ RENESAS TECHNOLOGY CORP ]
