ZLF645 MAXIM [Maxim Integrated Products], ZLF645 Datasheet - Page 31

• Manufacturer Part Number: ZLF645
• Description: Flash MCUs with Learning Amplification
• Manufacturer: MAXIM [Maxim Integrated Products]

ZLF645 Series Flash MCUs
Product Specification
23
Port 3
Port 3 is an 8-bit CMOS-compatible I/O port. Port 3 consists of four fixed inputs
(P33:P30), three fixed outputs (P37:P36:P35), and one multi-functioned pin (P34) that can
function as an output only or as a bidirectional open-drain I/O depending on whether the
ZLF645 MCU is in ICP mode.
P30, P31, P32, and P33 are standard CMOS inputs with option enabled pull-up transistors
and can be configured under software as interrupts, as received data input to the UART
block, as input to comparator circuits, or as input to the IR learning amplifier.
P37, P36, and P35 are push/pull outputs and can be configured as outputs from
counter/timers and/or comparator circuits.
During the ZLF645’s POR time, P34 is configured as an input pin with pull-up enabled. If
after completing it’s POR period, the ZLF645 has not detected this pin LOW and been put
into ICP mode, this pin will revert back to being a push/pull output only. For more details
on the function of pin P34, see
ICP Interface
on page 53.
PS026408-1208
Port 3