9100A-017
7-17
•
CE (which is controlled by PS7) has a setup time of 0 ns
prior to RD going low.
•
RD has a minimum pulse width of 200 ns.
•
Data D7 through D0 will be valid a maximum of 100 ns
after RD goes low.
•
Address bus A11 through A1 and CE have a 0 ns hold time
after RD goes high.
•
CE must be high for 300 ns between chip accesses.
The following 2674 Video Display Controller Read Cycle vector
file performs a read cycle.
2674 Video Display Controller Read Cycle
GROUPS [40-30,1][29-22][21-14][13][12][11][10][9][8][7][6][5-2]
DISPLAY HEX,HEX,HEX,BIN
! ADDR DATA CTRL UNUSED
! A11 - A1 D15-D8 D7-D0 R U L P P R V V
! / D D S S E W D
! W S S 7 6 S A T
! - - - - - E I A
! T T C
! - - K
! -
! READ CYCLE addr $f0011 (addr $fxxxx =PS7-, data = LDS-)
1 $011 $XX $XX 1 1 1 1 1 1 X X XXXX
2 $011 $XX $XX 1 1 0 0 1 1 X X XXXX
WAIT -
3 $003 $XX $XX 1 1 1 1 1 1 X X XXXX
CAPTURE
STOP
The first vector in this file sets the address. Vector 2, which is
driven 200 ns later holds the address holds R/W high and sets
LDS low (to get RD low), and sets PS7 low (to get CE low). The
WAIT statement ensures that VDTACK is returned before
continuing. The final vector, which is driven 200 ns later, holds
the address while the CTRL signals are changed to return RD
and CE high. Approximately 100 ns after RD and CE have
returned high (in the center of the vector period), the CAPTURE
clock clocks the data in on the data bus. A
readword
command
using the “stored” mode can then be performed to retrieve the
data. Note that the read data is only valid for 100 ns maximum
after the return of RD and CE to the high state. If the read
Summary of Contents for 9100A Series
Page 6: ...vi ...
Page 8: ...viii ...
Page 10: ...x ...
Page 14: ...9100A 017 1 4 ...
Page 24: ...9100A 017 3 6 ...
Page 44: ...9100A 017 5 4 ...
Page 58: ...9100A 017 6 14 ...
Page 83: ...A 1 Appendix A New TL 1 Commands ...
Page 84: ...9100A 017 A 2 ...
Page 87: ...clockfreq 3 For More Information The Overview Of TL 1 section of the Programmer s Manual ...
Page 88: ...clockfreq 4 ...
Page 91: ...drivepoll 3 For More Information The Overview Of TL 1 section of the Programmer s Manual ...
Page 92: ...drivepoll 4 ...
Page 104: ...vectordrive 4 ...
Page 107: ...vectorload 3 For More Information The Overview Of TL 1 section of the Programmer s Manual ...
Page 108: ...vectorload 4 ...
Page 116: ...9100A 017 C 2 ...
Page 117: ...9100A 017 C 3 ...
Page 118: ...9100A 017 C 4 ...