EM6605 EM Microelectronic, EM6605 Datasheet - Page 7

• Manufacturer Part Number: EM6605
• Description: 4 bit Microcontroller
• Manufacturer: EM Microelectronic

3.3. Input port (PA0..PA3) RESET
With a mask option it is possible to choose from four PortA reset combinations. The selected ports must be
simultaneously high for at least 2ms = t
debouncers. Note also, that RESET with port A is not possible during SLEEP mode.
Below are the combinations of Port A (PA0..PA3) inputs which can be used to generate a RESET. They
can be selected by metal « PortA RESET » mask option described in chapter 14.
Table 3.PortA Inputs RESET options
3.4. Watchdog Timer RESET
The Watchdog Timer RESET is a software option and if used it will generate a RESET if it is not cleared.
See section 5. Watchdog timer for details.
Table 4.Watchdog-Timer Option
3.5. CPU State after RESET
RESET initialises the CPU as shown in the Table below.
Table 5.Initial Value After RESET
name
Program counter 0
Program counter 1
Program counter 2
stack pointer
index register
Carry flag
Zero flag
HALT
Instruction register
periphery registers
Watchdog Function
Without Watchdog Time-out reset
With Watchdog Time-out reset
Option C
Option D
Option A
Option B
Function
no inputs RESET
RESET = PA0 * PA1
RESET = PA0 * PA1 * PA2
RESET = PA0 * PA1 * PA2 * PA3
bits
12
12
12
2
7
1
1
1
16
4
symbol
PC0
PC1
PC2
SP
IX
CY
Z
HALT
IR
NoWD bit in Option register
1
0
debS
/ 16ms = t
initial value
$000 (as a result of Jump 0)
undefined
undefined
SP(0) selected
undefined
undefined
undefined
0
Jump 0
see peripheral memory map
Opt. Code
RA0
RA1
RA2
RA3
debL
(*f1) (CLK = 32kHz) due to the presence of
© EM Microelectonic-Marin SA, 02/99, Rev. B/243
EM6605
7