What are the differences when using the I/Os on the HT48XA0-2, HT48XA0-1 and HT48XA1, HT48XA3, HT48XA5 devices?
Answer The PA port on the HT48XA0-2 and HT48XA0-1 devices is the most simple port and is an NMOS type output or Schmitt Trigger input. When used as an input it is important to note that before reading the port the output should be set to a “1”. To do this use the SET [m].i”(PA: 0~7) instruction to disable the NMOS output and then use the MOV A [m] instruction to get the input data. The PA port on the HT48XA1, HT48XA3 and HT48XA5 is a more complicated CMOS type output or Schmitt Trigger input. Whether the port is used as an output or input is determined by the PAC special port control register. As an example if PAC.0 is equal to “1” then bit 0 of PA will be setup as an input, if PAC.0 is equal to “0” then bit 0 of PA will be setup as an output.
Related Questions
- In the HT48XA0-2 and HT48XA0-1 series of devices when "0" is written to bit 7~6 of the memory pointer MP, when it is read out, why does it give a value of "1"?
- For the HT48XA0-1/2 MCU devices, are their any differences in operation between the Mask devices and OTP devices?
- What are the differences when using the I/Os on the HT48XA0-2, HT48XA0-1 and HT48XA1, HT48XA3, HT48XA5 devices?
