In the maximum mode, the 8086 is operated by connecting the MN MX pin to ground. In
this mode, the processor derives the status signals S2 , S1 and S0 . Another chip called bus
controller derives the control signals using this status information.In the maximum mode, there may be more than one microprocessor in the system configuration. The other components in the system are the same as in the minimum mode system.The basic functions of the bus controller chip IC8288, is to derive control signals like RD and WR (for memory and I/O devices), DEN , DT R , ALE, etc. using the information made available by the processor on the status lines.The bus controller chip has input lines S2 , S1 , S0 and CLK. These inputs to 8288 are driven by the CPU. It derives the outputs ALE, DEN , DT R,MRDC ,MWTC, AMWC ,IORC , IOWC and AIOWC . The AEN , IOB and CEN pins are specially useful for multiprocessor systems. AEN and IOB are generally grounded. CEN pin is usually lied to +5V. The significance of the MCE PDEN output depends upon the status of the IOB pin.If IOB is grounded, it acts as master cascade enable to control cascaded 8259A, else it acts
as peripheral data enable used in the multiple bus configurations. INTApin is used to issue two interrupt acknowledge pulses to the interrupt controller or to an interrupting device. IORC , IOWC are I/O read command and I/O write command signals respectively. These signals enable an IO interface to read or write the data from or to the addressed port. The MRDC , MWTC are memory read command and memory write command signals respectively and may be used as memory read and write signals. All these command signals instruct the memory to accept or send data from or to the bus. For both of these write command signals, the advanced signals namely AIOWC and AMWTC are available. They also serve the same purpose, but are activated one clock cycle earlier than the IOWCand MWTC signals, respectively. The maximum mode system is The maximum mode system timing diagrams are also divided in two portions as read (input) and write (output) timing diagrams. The address/data and address/status timings are similar to the minimum mode. ALE is asserted in T1, just like minimum mode. The only difference lies in the status signals used and the available control and advanced command signals. Maximum mode timings for the read operation while same for the write operation.
this mode, the processor derives the status signals S2 , S1 and S0 . Another chip called bus
controller derives the control signals using this status information.In the maximum mode, there may be more than one microprocessor in the system configuration. The other components in the system are the same as in the minimum mode system.The basic functions of the bus controller chip IC8288, is to derive control signals like RD and WR (for memory and I/O devices), DEN , DT R , ALE, etc. using the information made available by the processor on the status lines.The bus controller chip has input lines S2 , S1 , S0 and CLK. These inputs to 8288 are driven by the CPU. It derives the outputs ALE, DEN , DT R,MRDC ,MWTC, AMWC ,IORC , IOWC and AIOWC . The AEN , IOB and CEN pins are specially useful for multiprocessor systems. AEN and IOB are generally grounded. CEN pin is usually lied to +5V. The significance of the MCE PDEN output depends upon the status of the IOB pin.If IOB is grounded, it acts as master cascade enable to control cascaded 8259A, else it acts
as peripheral data enable used in the multiple bus configurations. INTApin is used to issue two interrupt acknowledge pulses to the interrupt controller or to an interrupting device. IORC , IOWC are I/O read command and I/O write command signals respectively. These signals enable an IO interface to read or write the data from or to the addressed port. The MRDC , MWTC are memory read command and memory write command signals respectively and may be used as memory read and write signals. All these command signals instruct the memory to accept or send data from or to the bus. For both of these write command signals, the advanced signals namely AIOWC and AMWTC are available. They also serve the same purpose, but are activated one clock cycle earlier than the IOWCand MWTC signals, respectively. The maximum mode system is The maximum mode system timing diagrams are also divided in two portions as read (input) and write (output) timing diagrams. The address/data and address/status timings are similar to the minimum mode. ALE is asserted in T1, just like minimum mode. The only difference lies in the status signals used and the available control and advanced command signals. Maximum mode timings for the read operation while same for the write operation.
$$$$$$ Yesterday is not ours to recover, but tomorrow is ours to win or lose.$$$$$$ @Lyndon B. Johnson
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