IPMC7xx ISA Bus Resources
http://www.motorola.com/computer/literature 1-35
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Z85230 ESCC and Z8536 CIO Registers and Port Pins
The Z85230 ESCC is used to provide the two sync/async serial ports on
some MVME5100 series models. The PCLK which can be used to obtain
the baud rates, is 10 MHz. Refer to the SCC U ser’s Manual for
programming information on the Z85230 ESCC device.
The Z8536 CIO is used to provide the modem control lines not provided
by the Z85230 ESCC and a method to inquire the module ID of the two
sync/async serial ports that reside on the MVME761 module. Refer to the
Z8536 Data Sheet for programming information.
Z8536/Z85230 Registers
Accesses to the Z8536 CIO and the Z85230 ESCC are accomplished via
Port Control and Port Data Registers. The PCLK to the Z8536 is 5 MHz.
Also, a Pseudo IACK Register is also defined to retrieve interrupt vectors
from these devices. The Z8536 CIO has higher priority than the Z85230
ESCC in the interrupt daisy chain. The followin g list the registers
associated with accessing these two dev ices:
Table 1-19. Z8536/Z85230 Access Registers
PCI I/O Address Function
0000 0840 Z85230: Port B (Serial Port 4) Control
0000 0841 Z85230: Port B (Serial Port 4) Data
0000 0842 Z85230: Port A (Serial Port 3) Control
0000 0843 Z85230: Port A (Serial Port 3) Data
0000 0844 Z8536 CIO: Port C’s Data Register
0000 0845 Z8536 CIO: Port B’s Data Register
0000 0846 Z8536 CIO: Port A’s Data Register
0000 0847 Z8536 CIO: Control Register
0000 084F Z85230/Z8536 Pseudo IACK