Z86017/Z16017 PCMCIA Interface Solution
Product Specification
4
use the physical PCMCIA 68-pin connector but do not support PCMCIA
protocol. If this pin is held High (PC_ATA/HOE), the device is placed
into the PCMCIA mode. The override bits in register 00H determine what
mode(s) the user can support.
Serial Port Operation (Master) Mode
After the ZX6017 determines that an external EEPROM is present (see
Figure 2), the Ready/Busy pin on the PCMCIA interface is set to Busy.
The ZX6017 internal sequencer starts up and reads EEPROM address
1eh. If EEPROM address 1Eh is loaded with a 1Ch then the EEPROM’s
data is considered to be valid. After that, the internal sequencer resets its
address counter back to zero. Data from EEPROM’s addresses [00-2F] is
read out and put into the on-board registers of the ZX6017. The EEPROM
sequencer then reads EEPROM addresses 30h to FFh and each byte is
moved into the ZX6017 on-board attribute memory addresses 00-CFh.
After loading the registers and attribute memory, the sequencer completes
by clearing the Ready/Busy pin on the PCMCIA interface indicating 1
“Ready.” If EEPROM address 1Eh does not contain 1Ch, then the
sequencer stops. The PCMCIA Ready/Busy pin stays in the Busy state,
the on-board registers of the ZX6017 remain in their default state, and
attribute memory data is unknown. The user can program the off-board
EEPROM through the PCMCIA interface by means of three special
registers and ignore Busy.
PS012002-1201
PCMCIA Interface Overview
ZILOG [ ZILOG, INC. ]
