dac1008 National Semiconductor Corporation, dac1008 Datasheet - Page 17

• Manufacturer Part Number: dac1008
• Description: Up Compatible, Double-buffered D To A Converters
• Manufacturer: National Semiconductor Corporation

Figure 18 illustrates the simplicity of interfacing the
7 0 MICROPROCESSOR INTERFACE
The logic functions of the DAC1006 family have been ori-
ented towards an ease of interface with all popular mPs The
following sections discuss in detail a few useful interface
schemes
7 1 DAC1001 1 2 to INS8080A Interface
DAC1006 to an INS8080A based microprocessor system
FIGURE 18 Interfacing the DAC1000 to the INS8080A CPU Group
NOTE DOUBLE BYTE STORES CAN BE USED
e g THE INSTRUCTION SHLD F001 STORES THE L
REG INTO B1 AND THE H REG INTO B2 AND
TRANSFERS THE RESULT TO THE DAC REGISTER
THE OPERAND OF THE SHLD INSTRUCTION MUST
BE AN ODD ADDRESS FOR PROPER TRANSFER
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The circuit will perform an automatic transfer of the 10 bits
of output data from the CPU to the DAC register as outlined
in Section 6 2 1 ‘‘Controlling Data Transfer for an 8-Bit Data
Bus ’’
Since a double byte write is necessary to control the DAC
with the INS8080A a possible instruction to achieve this is a
PUSH of a register pair onto a ‘‘stack’’ in memory The 16-
bit register pair word will contain the 10 bits of the eventual
DAC input data in the proper sequence to conform to both
TL H 5688 – 24