Ampro Corporation Single Board Computer Littleboard 550 - Manual (Page 46)

Chapter 3 Hardware
40 Reference Manual LittleBoard 550
Pin # Signal Description
31 PDD15 Disk Data 15 – Refer to PDD3 on pin-2 for more information.
32 PDCE2* Primary Slave/Master Chip Select – This signal, along with CE1*, selects the
CompactFlash card and indicates to the card when a byte or word operation is
being performed. This signal always accesses the odd byte of the word.
33 NC Not Connected (VS1*)
34 PDIOR* Primary I/O Read Strobe – This signal is generated by the host and gates the
I/O data onto the bus from the CompactFlash card when the card is
configured to use the I/O interface.
35 PDIOW* Primary I/O Write Strobe – This signal is generated by the host and clocks the
I/O data on the Card Data bus into the CompactFlash card controller registers
when the card is configured to use the I/O interface. The clock occurs on the
negative to positive edge of the signal (trailing edge).
36, 38 VCC CF power – This voltage is determined by setting of JP3, CF Voltage Select
(pins 1-2 = +5 volts ±5% Default, or pins 2-3 = +3.3 volts ±5%)
37 IRQ14 Interrupt Request 14 – IRQ 14 is asserted by drive (CF) when it has a pending
interrupt (PIO transfer of data to or from the drive to the host).
39 Master* Master/Slave – This pin determines the Master or Slave configuration of the
CompactFlash by the jumper (JP4) setting. When this pin is grounded
(jumper inserted), this device is configured as Master. When this pin is open
(jumper removed), this device is configured as Slave.
40 NC Not Connected (VS2*)
41 PDRST* Primary IDE Reset – This input signal is the active low hardware reset from
the host. If this pin goes high, it is used as the reset signal. This pin is driven
high at power-up, causing a reset, and if left high will cause another reset.
42 PDIORDY Primary I/O-DMA Channel Ready – When negated, extends the host transfer
cycle of any host register access when the drive is not ready to respond to a
data transfer request. High impedance if asserted.
43 NC Not Connected (INPACK)
44 VCC CF power – This voltage is determined by setting of JP3, CF Voltage Select
(pins 1-2 = +5 volts ±5% Default, or pins 2-3 = +3.3 volts ±5% )
45 NU Not used (Pull-up to VCC through 10k ohm resistor)
46 PD33/66 UDMA 33/66 Sense – Senses which DMA mode to use for the CF card.
47 D8 Disk Data – These signals (0 to 15) provide the disk data signals
48 D9 Disk Data – These signals (0 to 15) provide the disk data signals
49 D10 Disk Data – These signals (0 to 15) provide the disk data signals
50 GND Ground
Notes: The shaded area denotes power or ground. The signals marked with * = Negative true logic.
CAUTION To prevent system hangs when using older CompactFlash cards,
ensure your CompactFlash is compatible with UDMA 100 IDE
hard disk drives. Consult your CompactFlash card vendor for
UDMA 100 compatibility.