M69030 Asiliant Technologies, M69030 Datasheet - Page 161

• 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

GR04
read/write at I/O address 3CFh with index at address 3CEh set to 04h
shared by both pipelines A and B
7-2
1-0
`efmp
A
&
B

Reserved
Read Plane Select
69030 Databook
7
Read Plane Select Register
These two bits select the memory plane from which the CPU reads data in Read Mode 0.
In Odd/Even Mode, bit 0 of this register is ignored. In Chain 4 Mode, both bits 1 and 0 of
this register are ignored. The four memory planes are selected as follows:
These two bits also select which of the four memory read latches may be read via the
Memory Read Latch Data Register (CR22). The choice of memory read latch corresponds
to the choice of plane specified in the table above. The Memory Read Latch Data register
and this additional function served by 2 bits are features of the VGA standard that were
never documented by IBM.
6
5
Reserved
Graphics Controller Registers
Bits
1 0
0 0
0 1
1 0
1 1
4
Plane Selected
Plane 0
Plane 1
Plane 2
Plane 3
3
2
Revision 1.3 11/24/99
Read Plane Select
1
0
11-5