NS486SXF Datasheet, PDF (14/44 Pages) National Semiconductor (TI) – NS486TMSXF Optimized 32-Bit 486-Class Controller with On-Chip Peripherals for Embedded Systems

2 0 Pin Description Tables (Continued)
TABLE 2-12 HP-SIR UART Pins
Symbol
Tx
Rx
UCLK
Pins
57
58
59
Type
O
I
O
Function
UART Transmit data In HP-SIR mode this pin is the UART output encoded for the serial infrared link
Otherwise it is the transmit output of the 16550 UART
UART Receive data In HP-SIR mode this pin is routed through the serial infrared decoder Otherwise it
is the receive input to the 16550
Uart CLocK Output of programmable rate UART MODEM clock Typically used for the Infrared
Modulator
TABLE 2-13 PCMCIA Pins
Symbol
Pins Type
Function
CD RST
68
O CarD ReSeT This active high signal resets the PCMCIA card during a soft-reset
IOIS16 WP
67
I IO port IS 16 bits Write Protect When a PCMCIA card is configured as an IO card this signal
is asserted to indicate the currently addressed IO port is 16 bits wide When a PCMCIA card is
configured as a memory card an active high signal indicates the card is currently write
protected
BVD2 SPKR
74
I Battery Voltage Detect bit 2 SPeaKeR output When a PCMCIA card is configured as a
memory card this input along with BVD 1 will provide status information about the card’s on-
board battery condition When a PCMCIA card is configured as an IO card this pin will act as
the audio output of the card to the system
BVD1 STSCNG 73
I Battery Voltage Detect bit 1 STatuS ChaNGe output When a PCMCIA card is configured as a
memory card this input along with BVD 2 will provide status information about the card’s on-
board battery state When a PCMCIA card is configured as an I O card the status change
signal indicates one or more of the memory status signals (BVD 2 1 WP RDY or BSY) has
changed states
V_CC SEL
69
O PCMCIA V_CC SELect When this signal is low the V_CC power to the PCMCIA card should be
enabled
V_PP SEL1
V_PP SEL2
GPI
CD2 CD1
70 71 O PCMCIA V_PP SELect 1 and 2 These signals indicate the voltage with which the V_PP power to
the PCMCIA card should be driven
72
I General Purpose Input This signal is a general purpose input signal used with a PCMCIA card
to indicate a valid V_PP state a pending card eject insertion or as an interrupt source
76 75 I Card Detect Both signals are low when the PCMCIA card is correctly inserted
DIR
77
O DIRection Used to control the direction of the data line buffers to the PCMCIA interface
ENABLE
78
O ENABLE PCMCIA Enables the buffer drivers to the PCMCIA interface Low true signal
REG
79
O REG PCMCIA card support
Note If PCMCIA is enabled Chip Selects 1 and 2 become Card Enable 1 and 2 See Table 2-17 ‘‘General Purpose Chip Select Pins’’ Also IRQ 5 becomes the
PCMCIA IREQ signal
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