Rainbow Electronics T89C51RD2 - Manual (Page 42)

42 Rev. F - 15 February, 2001
T89C51RD2
This table shows the state of ports during idle and power-down modes.
* Port 0 can force a 0 level. A "one" will leave port floating.
Mode
Program
Memory
ALE PSEN PORT0 PORT1 PORT2 PORT3
Idle Internal 1 1 Port Data* Port Data Port Data Port Data
Idle External 1 1 Floating Port Data Address Port Data
Power Down Internal 0 0 Port Dat* Port Data Port Data Port Data
Power Down External 0 0 Floating Port Data Port Data Port Data