xr17c152im Exar Corporation, xr17c152im Datasheet - Page 17

• Manufacturer Part Number: xr17c152im
• Description: 5v Pci Bus Dual Uart
• Manufacturer: Exar Corporation

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REV. 1.2.0
REGB [23:16] (default 0x00)
REGB register provides a control for simultaneous write to both UARTs configuration register or individually.
This is very useful for device initialization in the power up and reset routines. Also, the register provides a
facility to interface to the non-volatile memory device such as a 93C46 EEPROM. In embedded applications,
the user can use this facility to store proprietary data.
The 152 provides 8 multi-purpose inputs/outputs [MPIO7:0] for general use. Each pin can be programmed to
be an input or output function. The input logic state can be set for normal or inverted level, and optionally set to
generate an interrupt. The outputs can be set to be normal HIGH or LOW state, or three-state. Their functions
and definitions are programmed through 5 registers: MPIOINT, MPIOLVL, MPIO3T, MPIOINV and MPIOSEL. If
all 8 pins are set for inputs, all 8 interrupts would be or’ed together. The Or’ed interrupt is reported in the
channel 0 UART interrupt status, see Interrupt Status Register. The pins may also be programmed to be
outputs and to the three-state condition for signal sharing.
Bit 7 represents MPIO7 pin and bit 0 represents MPIO0 pin. There are 5 registers that select, control and
monitor the 8 multipurpose inputs and output pins.
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REGB[16] (Read/Write)
REGB[19:17]
REGB[20] (Write-Only)
REGB[21] (Write-Only)
REGB[22] (Write-Only)
REGB[23] (Read-Only)
1.2.8
1.2.9
1.2.10
REGB Register
Multi-Purpose Inputs and Outputs
MPIO REGISTER
Logic 0 (default) write to each UART configuration registers individually.
Logic 1 enables simultaneous write to both UARTs configuration register.
Reserved.
Control the EECK, clock, output (pin 84) on the EEPROM interface.
Control the EECS, chips select, output (pin 83) to the EEPROM device.
EEDI (pin 82) data input. Write data to the EEPROM device.
EEDO (pin 81) data output. Read data from the EEPROM device.
Figure 6
17
shows the internal circuitry.
5V PCI BUS DUAL UART
XR17C152