TS87C51RD2 ATMEL Corporation, TS87C51RD2 Datasheet - Page 45

• Manufacturer Part Number: TS87C51RD2
• Description: (TS8xC51Rx2) High Performance 8-bit Microcontroller
• Manufacturer: ATMEL Corporation

Figure 6-14. Power-Down Exit Waveform
4188E–8051–08/06
XTAL1
INT0
INT1
Active phase
Exit from power-down by reset redefines all the SFRs, exit from power-down by external inter-
rupt does no affect the SFRs.
Exit from power-down by either reset or external interrupt does not affect the internal RAM
content.
Note:
Table 6-20.
* Port 0 can force a "zero" level. A "one" will leave port floating.
Power-down
Power-down
Mode
Idle
Idle
If idle mode is activated with power-down mode (IDL and PD bits set), the exit sequence is
unchanged, when execution is vectored to interrupt, PD and IDL bits are cleared and idle mode is
not entered.
Program
Memory
External
External
The state of ports during idle and power-down mode
Internal
Internal
Power-down phase
ALE
1
1
0
0
Oscillator restart phase
PSEN
1
1
0
0
Port Data*
Port Data*
Floating
Floating
PORT0
Active phase
Port Data
Port Data
Port Data
Port Data
PORT1
AT/TS8xC51Rx2
Port Data
Port Data
Port Data
Address
PORT2
Port Data
Port Data
Port Data
Port Data
PORT3
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