TTL or RS-232?


I’m confused about the serial connection to the WIZ145SR. The datasheet indicates RS-232 for the serial architecture but then indicates that serial data port interface is TTL. Wiki indicates that RS-232 uses +3V to +15V for 0 and -3V to -15V for 1. TTL is 0V for 0 and 3.3V or 5V for 1. Can you please clarify if the WIZ145SR uses RS-232 signaling and voltages?



Looking at the schematic for the test board:

Based on the use of level shifters connecting the UARTs to the DB-9s, I’m assuming that the voltages are TTL 0V to 3.3V representing 0 and 1 respectively.

Can you confirm that?