Question: Do the RW/WR pins on the AN2135S function the same way as described for the AN2131Q?
Answer: Yes, the RD and WR pins on the 2135 function the same as the AN2131Q. On page 45-334 of the TRM, table 1-3, shows the RD pin and the WR pin as active for this chip. The RD pin is pin number 21 and the WR pin is pin number 20.
1. For the WR pin, multiplexed pin whose function is selected by the WR bit of the PORTCCFG register. If WR=0, the pin is the bi-directional I/O port bit PC6. If WR=1, the pin is the active-low write signal for external memory. If the WR# signal is used, it should be externally pulled up to Vcc to ensure that the write strobe is inactive at power-on.
2. For the RD pin, multiplexed pin whose function is selected by the RD bit of the PORTCCFG register. If RD#=0, the pin is the bi-directional I/O port bit PC7. If RD#=1, the pin is the active-low read signal for external memory. If the RD# signal is used, it should be externally pulled up to Vcc to ensure that the read strobe is inactive at power-on.
