Datasheet
621
• Bits 5 and 4—PB2 Mode (PB2MD1 and PB2MD0): PB2MD1 and PB2MD0 select the
function of the PB2/IRQ0/POE0/RAS pin.
Bit 5: PB2MD1 Bit 4: PB2MD0 Description
0 0 General input/output (PB2) (initial value)
1 Interrupt request input (IRQ0)
1 0 Port output enable (POE0)
1 Row address strobe (RAS) (PB2 in single chip mode)
• Bit 3—Reserved: This bit always reads as 0. The write value should always be 0.
• Bit 2—PB1 Mode (PB1MD): Selects the function of the PB1/A17 pin.
Bit 2: PB1MD Description
0 General input/output (PB1) (initial value) (A17 in on-chip ROM invalid mode)
1 Address output (A17) (PB1 in single chip mode)
• Bit 1—Reserved: This bit always reads as 0. The write value should always be 0.
• Bit 0—PB0 Mode (PB0MD): Selects the function of the PB0/A16 pin.
Bit 0: PA0MD Description
0 General input/output (PB0) (initial value) (A16 in on-chip ROM invalid mode)
1 Address output (A16) (PB0 in single chip mode)