EM6603
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/16ms (CLK = 32kHz) due to the presence of 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
(metal Hardware option)
Option A
Option B
Option C
Option D
Function
no inputs RESET
RESET = PA0 * PA1
RESET = PA0 * PA1 * PA2
RESET = PA0 * PA1 * PA2 * PA3
Opt. Code
RA0
RA1
RA2
RA3
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
(software option)
Watchdog Function
Without Watchdog Time-out reset
With Watchdog Time-out reset
NoWD
bit in
Option
register
1
0
3.5
CPU State after RESET
RESET initialises the CPU as shown in the Table 5 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
bits
12
12
12
2
7
1
1
1
16
4
symbol
PC0
PC1
PC2
SP
IX
CY
Z
HALT
IR
initial value
$000 (as a result of Jump 0)
undefined
undefined
SP(0) selected
undefined
undefined
undefined
0
Jump 0
see peripheral memory map
03/02 REV. G/439
Copyright
2002, EM Microelectronic-Marin SA
7
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EMMICRO [ EM MICROELECTRONIC - MARIN SA ]
