The next two figures illustrates the reading process for an associative memory. First, the mask and MBR registers are loaded. The mask tells which bits of the MBR must match with some word in memory. Whereever there is a 1 in the mask, the corresponding bit of the MBR must match a word in memory. If there is a 0, no match is done. Thus, the mask tells which part of the MBR is the "key" and which part is the "value". Fig. 12.7.2 shows this.