A synchronous 4-bit up/down decade counter symbol (74LS192) in accordance with ANSI/IEEE Std. 91-1984 and IEC Publication 60617-12.

This logic symbol is based on the TI SN74LS192 datasheet.

This was the first edition of the TTL Data Book that used the IEEE Std. 91 symbols. Volume 1 contained a tutorial on how to read and create these symbols.[1] The tutorial was written by Fred Mann, the TI representative on IEEE subcommittee that created this style of symbols. He was also on the IEC technical committee.

This symbol is also similar to figure 5.13-16 in IEEE Std 91A-1991.