2/Theory of Operation
2-22
module output to an unchanging state. There are two methods by which the
Vector Pattern RAM and the Vector Control RAM can be selected:
o To drive vectors, the DRV/LD- signal must be set high by performing
a write to the U5 register 0 ($D0X01) with bit 3 set high. This
causes all outputs of U11 (BYTE0- through BYTE9-) and the BYTE10-
output of U10 to be low, thereby selecting all vector RAM.
o To load the Vector Pattern and Control RAM, the DRV/LD- signal must
be set low by performing a write to the U5 register ($D0X01) with
bit 3 set low. Only the RAM addressed by the chip counter U9 is
selected.
CHIP COUNTER OPERATION
The output of the chip counter is decoded by U10 and U11 to determine
which BYTEx- to set low when loading the RAM. The counter is initialized
by setting the LOAD-RAM- output of U5 low (Write @ $D0X01, bit 7 low)
and toggling RAM-PORT- (Read @ $D0X41). This causes the four-bit binary
counter (U9) to parallel-load its preset value of 5. The LOAD-RAM-
signal can then be returned high. When the output of the chip counter is
5, the BYTE0- output of the U11 PAL selects static RAM chip U100. A
write to RAM-PORT- causes the selected RAM to load the data on the bus
and advances the chip counter U9 output to 6, causing U11 output BYTE1-
to select U102. This operation is repeated until the counter reaches 15,
at which point the U10 PAL output BYTE10- selects the Control RAM U600.
Upon performing a write to RAM-PORT-, the Control RAM is loaded with the
data, and the RC0 output of U9 goes low.
The RC0 output is used as the DECREMENT- clock. The clock is routed to
the SSLOGIC block where it decrements the Vector RAM Address Register.
The RC0 output is also routed through U7 to reload the U9 chip counter
to the starting count of 5.
SSLOGIC (Start/Stop Logic) Functional Block
The SSLOGIC Functional Block consists of five groups of circuitry:
o Signal polarity/control register.
o Drive clock selection.
o Start/stop control.
o Handshake synchronization.
o Vector drive complete logic.
SIGNAL POLARITY/CONTROL REGISTER
The output section signal polarity and control is determined by the
values stored in register U6. The values are set by performing a write
to $D0Xll with the desired value. Table 2-9 contains the register bit
assignments. Bits 4 through 7 control the active edge polarity of the
externally supplied START, STOP, ENABLE, and DR CLK signals. Bit 3
Summary of Contents for 9100 Series
Page 6: ... iv ...
Page 8: ... vi ...
Page 15: ...2 Theory of Operation 2 3 Figure 2 1 Input Section Functional Block Diagram ...
Page 16: ...2 Theory of Operation 2 4 Figure 2 2 Output Section Functional Block Diagram ...
Page 19: ...2 Theory of Operation 2 7 Figure 2 3 Input Section Address Decoding Summary ...
Page 42: ...2 Theory of Operation 2 30 ...
Page 50: ...4 List of Replaceable Parts 4 2 ...
Page 54: ...4 List of Replaceable Parts 4 6 Figure 4 1 9100A 017 Final Assembly ...
Page 55: ...4 List of Replaceable Parts 4 7 Figure 4 1 9100A 017 Final Assembly cont ...
Page 57: ...4 List of Replaceable Parts 4 9 Figure 4 2 A1 Main PCA ...
Page 59: ...4 List of Replaceable Parts 4 11 Figure 4 3 A2 Top PCA ...
Page 64: ...4 List of Replaceable Parts 4 16 ...
Page 66: ...5 Schematic Diagrams 5 2 ...
Page 67: ...5 Schematic Diagrams 5 3 Figure 5 1 A1 Main PCA ...
Page 68: ...5 Schematic Diagrams 5 4 Figure 5 1 A1 Main PCA cont ...
Page 69: ...5 Schematic Diagrams 5 5 Figure 5 2 A2 Top PCA ...
Page 70: ...5 Schematic Diagrams 5 6 Figure 5 2 A2 Top PCA cont ...
Page 74: ...Index Index 4 ...