Inversion Signal Generation - Fujitsu MB86R02 Jade-D Hardware Manual

MB86R02 'Jade-D' Hardware Manual V1.64
Table 22-5 Function table for the Sync Mixer example
It is recommended that S4...S0 are listed in order of binary number representation. This makes it
possible to use the function result row directly as register contents for the Sync Mixer function table,
i.e. the last row is interpreted as binary 32 bit number with the LSB in the first row and the MSB in the
last. For the example this would be [xxxx xxxx xxxx xxxx xxxx xxxx 0000 1000] binary, with x's
denoting arbitrarily set or reset bits, since these will never be read out of the function table.
22.5.2.4.6 Sync Signal Delay Adjustment
Before the outputs of the twelve Sync Mixers are connected to actual GDC pins, they are fed through
a programmable delay stage. This allows the signals either to be left untouched or delayed for half a
pixel clock cycle. This delay can be set for each of the twelve Sync Mixer output signals individually
with the Sync Switch register.
22.5.2.5

Inversion Signal Generation

The purpose of the inversion signal INV is the minimization of total signal edge transitions on the RGB
data bus. Especially for TTL RGB signals this brings benefits for EMI.
The inversion signal is transmitted as accompanying signal to the output RGB data signals.
The input data of time (n - 1) is compared to the data at time n. If more than the half of the active RGB
bits have a transition from low to high or vice versa, then INV toggles between HIGH and LOW. When
INV is output as HIGH, all the bits of the current pixel are inverted.
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