CDP1853C3

The CDP1853/3 and CDP1853C/3 are high-reliability 1 of 8 decoders designed for use in general purpose microprocessor systems. These devices, which are functionally identical, are specifically designed for use as gated N-bit decoders and interface directly with the 1800-Series microprocessors without additional components. The CDP1853/3 has a recommended operating voltage range of 4V to 10.5V, and the CDP1853C/3 has a recommended operating voltage range of 4V to 6.5V.

When CHIP ENABLE (CE) is high, the selected output will be true (high) from the trailing edge of CLOCK A (high-to-low transition) to the trailing edge of CLOCK B (high-to-low transition). All outputs will be low when the device is not selected (CE = 0) and during conditions of CLOCK A and CLOCK B as shown in Figure 2. The CDP1853/3 inputs N0, N1, N2, CLOCK A, and CLOCK B are connected to 1800- series microprocessor outputs N0, N1, N2, TPA, and TPB respectively, when used to decode I/O commands as shown in Figure 5. The CHIP ENABLE (CE) input provides the capability for multiple levels of decoding as shown in Figure 6.

The CDP1853/3 can also be used as a general purpose 1 of 8 decoder for I/O and memory system applications as shown in Figure 4.