DS26303G-120 MAXIM [Maxim Integrated Products], DS26303G-120 Datasheet - Page 23

• Manufacturer Part Number: DS26303G-120
• Description: 3.3V, E1/T1/J1, Short-Haul, Octal Line Interface Unit
• Manufacturer: MAXIM [Maxim Integrated Products]

Figure 4-5. Serial Port Operation for Read Access with CLKE = 1
4.1.3 Parallel Port Operation
When using the parallel interface on the DS26303 the user has the option for either multiplexed bus operation or
nonmultiplexed bus operation. The ALE pin is pulled high in nonmultiplexed bus operation. The DS26303 can
operate with either Intel or Motorola bus-timing configurations selected by MOTEL pin. This pin being high selects
the Intel mode. The parallel port is only operational if MODESEL pin is pulled high. The following table lists all the
pins and their functions in the parallel port mode. See the timing diagrams in Section
Table 4-3. Parallel Port Mode Selection and Pin Functions
4.1.4 Interrupt Handling
There are four sets of events that can potentially trigger an interrupt. The interrupt functions as follows:
·
·
·
MODESEL, MOTEL,
When status changes on an interruptible event, the INTB pin will go low if the event is enabled through the
corresponding interrupt-enable register. INTB must be pulled high externally with a 10kW resistor for wired-OR
operation. If a wired-OR operation is not required, the INTB pin can be configured to be high when not active
by setting register GISC.INTM.
When an interrupt occurs, the host processor must read the interrupt status register to determine the source of
the interrupt. The read also clears the Interrupt Status register and clears the output INTB pin. The interrupt
status register can also be configured as clear-on-write as per register GISC.CWE. This clears INTB when a
clear-on-write is performed.
Subsequently, the host processor can read the corresponding status register to check the real-time status of
the event.
SDI
SDO
CSB
MUX
SCLK
100
110
101
111
0
(lsb)
1
A1
2
A2
3
Nonmultiplexed Motorola
Multiplexed Motorola
Nonmultiplexed Intel
PARALLEL HOST
A3
Multiplexed Intel
4
INTERFACE
A4
5
A5
6
A6
7
DS26303: 3.3V, T1/E1/J1, Short-Haul, Octal Line Interface Unit
(msb)
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X
8
CSB, ACKB, DSB, RWB, ASB, A [4:0], D [7:0], INTB
CSB, RDY, WRB, RDB, ALE, A [4:0], D [7:0], INTB
CSB, ACKB, DSB, RWB, ASB, AD [7:0], INTB
CSB, RDY, WRB, RDB, ALE, AD [7:0], INTB
D0
(lsb)
9
D1
10
ADDRESS, DATA, AND CONTROL
D2
11
D3
12
D4
13
10
D5
for more details.
14
D6
15
(msb)
D7
16