System Manual

GuidePort: System Manual 27. November 2000 Seite 14
Mounting of PCB and Position of Connectors:
It is of the utmost importance to mount the GP receiver board in a vertical position:
'Reset': reset is active when 'low', internal connection on GuidePort receiver PCB: MR of
MAX811 (pin 3)
'Interrupt_1 ': Interrupt_1 is active when 'low'. Mollie’s read or write procedures always start
with the interrupt request. The first interrupt tells the GP receiver that Mollie has
put an address word on the bus. During the power on procedure or a Reset from
Mollie the line must be in the high ohmic state or 'High'. Interrupt_1 is not allowed
if Interrupt_2 is active (low).
Connection on GP receiver: IRQA of DSP56303.
'Read/Write': When Mollie has activated the interrupt and put an address word on the bus, the
Read/Write line determines whether Mollie wants to read from or write into the
related register. 'High' means 'read', 'Low' means 'write'. Connection on GP
receiver: PB 8 of DSP 56 303.
8-bit parallel data: bi-directional data bus
Connection on GP receiver: PB 0.........PB 7 of DSP56303
LSB = PB 0, MSB = PB 7
'Frame Clock': The Frame Clock coming from the GuidePort receiver indicates that the receiver
has synchronized with the received bit stream and that real-time audio is
available.
'Frame Clock' = low: no synchronization, no audio
'Frame Clock' = high: frame synchronization has taken place, audio is available
'Interrupt_2': This is an impulse from the GuidePort receiver indicating Mollie that certain
conditions have been fulfilled. These conditions are:
Either • there is a change in the identifier number register
and/or • the bit error statistic exceeds the limit defined in the Error Limit
register (Bit Error Statistic Register)
and/or • a new GP Message is available(GP Message Register)
During register updating, Interrupt_2 is 'low'. As the time required is very short
(≈100ns), the detection of the Interrupt_2 signal should be edge controlled using
the positive edge. All above mentioned registers are updated within one write
cycle, which means that more than one register may change its content. This
makes sense because if there is an old error message in the GP Message
Register from the last update, it is now deleted if it is invalid (see also appended
flow charts).
Interrupt_2 is not allowed during Mollie’s Read/Write routines.
Pin 1
Pin 24
24FLZ connector for
GP/Mollie interface
Cable direction
Identifier
coil
Connectors for RF antennas