
Chapter 3 | Hardware |
Pin #
31
32
33
34
35
36, 38
37
39
40
41
42
43
44
45
46
47
48
49
50
Signal | Description |
PDD15 | Disk Data 15 – Refer to PDD3 on |
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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. |
NC | Not Connected (VS1*) |
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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. |
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). |
VCC | CF power – This voltage is determined by setting of JP3, CF Voltage Select |
| (pins |
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). |
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. |
NC | Not Connected (VS2*) |
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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 |
PDIORDY | Primary |
| cycle of any host register access when the drive is not ready to respond to a |
| data transfer request. High impedance if asserted. |
NC | Not Connected (INPACK) |
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VCC | CF power – This voltage is determined by setting of JP3, CF Voltage Select |
| (pins |
NU | Not used |
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PD33/66 | UDMA 33/66 Sense – Senses which DMA mode to use for the CF card. |
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D8 | Disk Data – These signals (0 to 15) provide the disk data signals |
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D9 | Disk Data – These signals (0 to 15) provide the disk data signals |
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D10 | Disk Data – These signals (0 to 15) provide the disk data signals |
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GND | Ground |
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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.
40 | Reference Manual | LittleBoard 550 |