tmp88ch40img TOSHIBA Semiconductor CORPORATION, tmp88ch40img Datasheet - Page 26

• Manufacturer Part Number: tmp88ch40img
• Description: 8 Bit Microcontroller
• Manufacturer: TOSHIBA Semiconductor CORPORATION

2.1 Functions of the CPU Core
2. Functional Description
Address Trap Control Register
Address Trap Control Code Register
(1F94H)
(1F95H)
ATKEY
ATAS
2.1.5.3
2.1.5.4
Note: Read-modify-write instructions, such as a bit manipulation, cannot access ATAS or ATKEY register because these register
are write only.
locked up. To prevent this problem, upon detecting "0" to SYSCR2 Register bit 7 or detecting "1" to
SYSCR2 Register bit 5, the device automatically generates an internal reset signal to let the system clock
continue oscillating.
ATKEY
ATAS
7
7
-
Watchdog Timer Reset
System Clock Reset
Note 1: In development tools, address trap cannot be prohibited in the internal RAM,SFR or DBR area with
Note 2: While the SWI instruction at an address immediately before the address trap area is executing, the
Development tool setting
Refer to the Section “Watchdog Timer.”
When SYSCR2 Register bit 7 is cleared to 0, the system clock is turned off, causing the CPU to become
• To prohibit the address trap:
the address trap control registers. When using development tools, even if the address trap permis-
sion/prohibition setting is changed in the user’s program, this change is ineffective. To execute
instructions from the RAM area, development tools must be set accordingly.
program counter is incremented to point to the next address in the address trap area; an address trap
is therefore taken immediately.
6
Select the address trap
permission / prohibition
6
Write control code to prohibit
address trap
-
1. Modify the iram (mapping attribute) area to (00040H to 000BFH) in the memory map win-
2. Set 000C0H to "address trap prohibition area" as a new eram (mapping attribute) area.
3. Load the user program
4. Execute the address trap prohibition code in the user’s program
dow.
5
5
-
4
4
-
0: Permit address trap
1: Prohibit address trap
D2H: Address trap prohibition code
Others: Ineffective
3
3
-
(It may be available after setting control code for ATKEY register)
Page 18
2
2
-
1
1
-
ATAS
0
0
(initial value: **** ***0)
(initial value: **** ****)
TMP88CH40IMG
Write
Write
only
only