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2. Specify memory ↔ I/O transfer mode and address increment/
decrement in the SM0, SM1, DM0 and DM1 bits of DMODE.
3. Load the number of bytes to transfer in BCR0
4. The DMA request sense mode (DMS0 bit in DCNTL) must be
specified as edge sense.
5. Enable or disable DMA termination interrupt with the DIE0 bit in
DSTAT.
6. Program DE0 =
1
the DMA operation with the ASCI begins under control of the ASCI
generated internal DMA request.
The ASCI receiver or transmitter using DMA is initialized to allow the
first DMA transfer to begin.
The ASCI receiver must be empty as shown by RDRF =
The ASCI transmitter must be full as shown by TDRE = 0. Thus, the first
byte is written to the ASCI Transmit Data Register under program
control. The remaining bytes are transferred using DMA.
Channel 1 DMA
DMAC Channel 1 performs memory to/from I/O transfers. Except for
different registers and status/control bits, operation is exactly the same as
described for channel 0 memory to/from I/O DMA.
To initiate a DMA channel 1 memory to/from I/O transfer, perform the
following operations:
1. Load the memory address (20 bits) into MAR1.
2. Load the I/O address (16 bits) into IAR1.
3. Program the source/destination and address increment/decrement
mode using the DIM1 and DIM0 bits in DCNTL.
(with DWE0 =
in the same access) in DSTAT and
0
Family MPU User Manual
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0
UM005004-0918
Z8018x
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Questions and answers
are there a timing diagrams for PUSH and POP instructions?
The timing diagrams for the PUSH and POP instructions for the ZiLOG Z8018 Series are as follows:
POP Instruction (e.g., POP IX or POP IY):
- Machine Cycle 1 (MC1): Fetch POP opcode.
- Machine Cycle 2 (MC2): Fetch address code.
- Machine Cycle 3 (MC3): Read from memory at SP (Stack Pointer); data goes to low byte (e.g., IXL or IYL).
- Machine Cycle 4 (MC4): Read from memory at SP+1; data goes to high byte (e.g., IXH or IYH).
PUSH Instruction (e.g., PUSH IX or PUSH IY):
- Machine Cycle 1 (MC1): Fetch PUSH opcode.
- Machine Cycle 2 (MC2): Fetch address code.
- Machine Cycle 3 (MC3): Decrement SP by 1 and write high byte (e.g., IXH or IYH) to memory at SP.
- Machine Cycle 4 (MC4): Decrement SP by 1 and write low byte (e.g., IXL or IYL) to memory at SP.
Each machine cycle includes three T-states (T1, T2, T3), and memory control signals (such as MREQ, RD, WR) are active as needed during these cycles.
This answer is automatically generated