z8f1621 ZiLOG Semiconductor, z8f1621 Datasheet - Page 176

• Manufacturer Part Number: z8f1621
• Description: High Performance 8-bit Microcontrollers
• Manufacturer: ZiLOG Semiconductor

PS019921-0308
DMA_ADC Operation
Configuring DMA_ADC for Data Transfer
3. Write the Start and End Register File address high nibbles to the DMAx End/Start
4. Write the lower byte of the Start Address to the DMAx Start/Current Address register.
5. Write the lower byte of the End Address to the DMAx End Address register.
6. Write to the DMAx Control register to complete the following:
DMA_ADC transfers data from the ADC to the Register File. The sequence of operations
in a DMA_ADC data transfer is:
1. ADC completes conversion on the current ADC input channel and signals the DMA
2. DMA_ADC requests control of the system bus (address and data) from the eZ8 CPU.
3. After the eZ8 CPU acknowledges the bus request, DMA_ADC transfers the two-byte
4. If the current ADC Analog Input is the highest numbered input to be converted:
Follow the steps below to configure and enable DMA_ADC:
1. Write the DMA_ADC Address register with the 7 most-significant bits of the Register
2. Write to the DMA_ADC Control register to complete the following:
Address High Nibble register.
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controller that two-bytes of ADC data are ready for transfer.
ADC output value to the Register File and then returns system bus control back to the
eZ8 CPU.
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If the current ADC Analog Input is not the highest numbered input to be converted,
DMA_ADC initiates data conversion in the next higher numbered ADC Analog Input.
File address for data transfers.
Select loop or single-pass mode operation
Select the data transfer direction (either from the Register File RAM to the on-
chip peripheral control register; or from the on-chip peripheral control register to
the Register File RAM)
Enable the DMAx interrupt request, if desired
Select Word or Byte mode
Select the DMAx request trigger
Enable the DMAx channel
DMA_ADC resets the ADC Analog Input number to 0 and initiates data
conversion on ADC Analog Input 0.
If configured to generate an interrupt, DMA_ADC sends an interrupt request to
the Interrupt Controller
Z8 Encore! XP
Direct Memory Access Controller
Product Specification
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F64XX Series
162