Что сказал - понял. Просто именно такая терминология используется в даташите к DS1631 и в других местах.
Цитата
Acknowledge (ACK): When a device is acting as a receiver, it must generate an acknowledge (ACK) on
the SDA line after receiving every byte of data. The receiving device performs an ACK by pulling the
SDA line low for an entire SCL period (see Figure 8). During the ACK clock cycle, the transmitting
device must release SDA. A variation on the ACK signal is the “not acknowledge” (NACK). When the
master device is acting as a receiver, it uses a NACK instead of an ACK after the last data byte to indicate
that it is finished receiving data. The master indicates a NACK by leaving the SDA line high during the
ACK clock cycle.
За указание другого термина спасибо. Сейчас попробую погуглить по нему