M69030 Asiliant Technologies, M69030 Datasheet - Page 129

• Manufacturer Part Number: M69030
• Manufacturer: Asiliant Technologies

Specifications of M69030

• Operating Temperature (min): 0C
• Operating Temperature Classification: Commercial
• Operating Temperature (max): 70C
• Rad Hardened: No
• Lead Free Status / Rohs Status: Supplier Unconfirmed

CR17
read/write at I/O address 3B5h/3D5h with index at address 3B4h/3D4h set to 17h
shadowed for pipelines A and B
7
6
5
4
`efmp
A
B
CRT Ctrl
CRT Ctrl

Reset
Reset
CRT Controller Reset
Word Mode or Byte Mode
Address Wrap
Reserved
69030 Databook
7
CR14
Bit 6
CRT Mode Control
0
0
1
1
0: Forces horizontal and vertical sync signals to be inactive. No other registers or outputs
are affected.
1: Permits normal operation.
0: The memory address counter’s output bits are shifted by 1 bit position before being
passed on to the frame buffer address decoder such that they are made into word-aligned
addresses when bit 6 of the Underline Location Register (CR17) is set to 0.
1: The memory address counter’s output bits remain unshifted before being passed on to
the frame buffer address decoder such that they remain byte-aligned addresses when bit
6 of the Underline Location Register (CR17) is set to 0.
Note: This bit is used in conjunction with bits 6 and 5 of the CRT Mode Control Register
(CR17) to control how frame buffer addresses from the memory address counter are
interpreted by the frame buffer address decoder as shown below:
See the note at the end of this register description.
0: Wrap frame buffer address at 16KB. This is used in CGA-compatible modes.
1: No wrapping of frame buffer addresses.
Note: This bit is only effective when word mode is made active by setting bit 6 in both the
Underline Location Register and this register to 0.
See the note at the end of this register description.
Byte Mode
Byte Mode
Word or
Word or
CR17
Bit 6
6
0
1
0
1
Word Mode -- addresses from the memory address counter are shifted
once to become word-aligned
Byte Mode -- addresses from the memory address counter are not shifted
Doubleword Mode -- addresses from the memory address counter are
shifted twice to become doubleword-aligned
Doubleword Mode -- addresses from the memory address counter are
shifted twice to become doubleword-aligned
Address
Address
Wrap
Wrap
5
CRT Controller Registers
Reserved
Reserved
4
Addressing Mode
Count By 2
Count By 2
3
Retrace Sel
Retrace Sel
Horizontal
Horizontal
2
Select Row
Select Row
Scan Cntr
Scan Cntr
Revision 1.3 11/24/99
1
Mode Supp.
Mode Supp.
Compat
Compat
0
9-27