NUTINY-SDK-M0516 Nuvoton Technology Corporation of America, NUTINY-SDK-M0516 Datasheet - Page 136

• Manufacturer Part Number: NUTINY-SDK-M0516
• Description: BOARD EVAL NUMICRO M051 SERIES
• Manufacturer: Nuvoton Technology Corporation of America
• Series: NuMicro M051™r
• Type: MCUr

Specifications of NUTINY-SDK-M0516

• Contents: Board, Cable
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: M051™ Series, M052/M054/M058/M0516

6.4.1.3 Open-Drain Mode Explanation
6.4.1.4 Quasi-bidirectional Mode Explanation
Set Px_PMD
digital output function but only with sink current capability, an additional pull-up resister is needed
for driving high state. If the bit value in the corresponding bit [n] of Px_DOUT is “0”, the pin drive a
“low” output on the pin. If the bit value in the corresponding bit [n] of Px_DOUT is “1”, the pin
output drives high that is controlled by the internal pull-up resistor or the external pull high
resistor.
Set Px_PMD
supports digital output and input function at the same time but the source current is only up to
hundreds uA. Before the digital input function is performed the corresponding bit in Px_DOUT
must be set to 1. The quasi-bidirectional output is common on the 80C51 and most of its
derivatives. If the bit value in the corresponding bit [n] of Px_DOUT is “0”, the pin drive a “low”
output on the pin. If the bit value in the corresponding bit [n] of Px_DOUT is “1”, the pin will check
the pin value. If pin value is high, no action takes. If pin state is low, then pin will drive strong high
with 2 clock cycles on the pin and then disable the strong output drive and then the pin status is
control by internal pull-up resistor. Note that the source current capability in quasi-bidirectional
mode is only about 200uA to 30uA for VDD is form 5.0V to 2.5V
NuMicro M051
(PMDn[1:0]) to 2’b10 the Px[n] pin is in Open-Drain mode and the I/O pin supports
(PMDn[1:0]) to 2’b11 the Px[n] pin is in Quasi-bidirectional mode and the I/O pin
Port Latch
Data
Input Data
™
Figure 6.4-2 Open-Drain Output
Series Technical Reference Manual
N
- 136 -
Publication Release Date: Sep 14, 2010
Port Pin
Revision V1.2