M69030 Asiliant Technologies, M69030 Datasheet - Page 163

• 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

4
`efmp

Odd/Even Mode
69030 Databook
This alternating pattern is meant to accommodate the use of the Odd/Even mode of
organizing the 4 memory planes, which is used by standard VGA modes 2h and 3h.
1, x: Four bits of data at a time from parallel bytes in each of the 4 memory planes are
transferred to the palette in a pattern that iterates per byte through memory planes 0
through 3. First the 4 most significant bits of a byte in memory plane 0 are transferred via
the 4 serial output bits, followed by the 4 least significant bits of the same byte. Next, the
same transfers occur from the parallel byte in memory planes 1, 2 and lastly, 3. Each
transfer provides either the upper or lower half of an 8 bit value for the color for each pixel,
making possible a choice of 1 of 256 colors per pixel.
This pattern is meant to accommodate mode 13h, a standard VGA 256-color graphics
mode.
0: Addresses sequentially access data within a bit map. The choice of which map is
accessed is made according to the value of the Plane Mask Register (SR02).
1: The frame buffer is mapped so that address bit 0 is used to select between sets of planes
such that even addresses select memory planes 0 and 2 and odd addresses select memory
planes 1 and 3.
Note: This works in a way that is the inverse of (and is normally set to be the opposite of)
bit 2 of the Memory Mode Register (SR04).
Serial Out 1st Xfer
Bit 3
Bit 2
Bit 1
Bit 0
plane 0
plane 0
plane 0
plane 0
bit 7
bit 6
bit 5
bit 4
plane 0
plane 0
plane 0
plane 0
Graphics Controller Registers
Xfer
bit 3
bit 2
bit 1
bit 0
2nd
plane 1
plane 1
plane 1
plane 1
Xfer
bit 7
bit 6
bit 5
bit 4
3rd
4th Xfer 5th Xfer 6th Xfer 7th Xfer 8th Xfer
plane 1
plane 1
plane 1
plane 1
bit 3
bit 2
bit 1
bit 0
plane 2
plane 2
plane 2
plane 2
bit 7
bit 6
bit 5
bit 4
plane 2
plane 2
plane 2
plane 2
bit 3
bit 2
bit 1
bit 0
plane 3
plane 3
plane 3
plane 3
bit 7
bit 6
bit 5
bit 4
Revision 1.3 11/24/99
plane 3
plane 3
plane 3
plane 3
bit 3
bit 2
bit 1
bit 0
11-7