HD6845SP Renesas Electronics America, HD6845SP Datasheet - Page 20

• Manufacturer Part Number: HD6845SP
• Description: CRT Controller
• Manufacturer: Renesas Electronics America

Specifications of HD6845SP

• Power Supply Type: Analog
• Typical Operating Supply Voltage: 5 V
• Minimum Operating Supply Voltage: 4.75 V
• Maximum Operating Supply Voltage: 5.25 V

COMPATIBILITY OF HD6845S AND HD6845R
Non-interlace Mode
Interlace Sync Mode
Interlace sync & Video mode control
2
3
4
5
Hitachi HD6845 Cathode Ray Tube Controller
http://andercheran.aiind.upv.es/~amstrad/docs/hd6845s/hd6845sp.htm (20 of 20)4/15/2004 11:36:03 AM
Vertical Sync Pulse
Width (VSYNC output)
SKEW function
Start Address Register
RESET signal (/RES)
These functions added to HD6845S utilitize undefined bits of the Control Register in HD6845R. If "0" is
programmed to the undefined bits in the initial set, it is possible to replace HD6845R with HD6845S without
changing the parameters. (The restriction on programming of HD6845S and HD6845R should be taken into
consideration).
Fixed at 16 raster scan cycle (16H)
Not included
Impossible to READ
MA0-MA13 Output, RA0-RA4 -
Synchronous Reset
Other Outputs - Asynchronous Reset
Output signals of MA0-MA13, RA0-RA4
synchronising with DLK "low" level, go to
"low" level after /RES has gone to "low".
Other outputs go to "low" immediatly after /
RES has gone to "low"level.
Fully compatible with HD6845R (note 1). HD6845R can be directly replaced by
HD6845S in these modes.
Not compatible with HD6845R in regard to programming and data for vertical
direction need to be changed.
Programmable (1-16 raster scan cycle
SKEW function is newly included in
DISPTMG, CUDISP signals
Possible to READ
MA0-MA13 Output, RA0-RA4, Other
Outputs - Asynchronous Reset
Output signals of MA0-MA13, RA0-RA4
and others go to "low" level immediatly
after /RES has gone to "low" level.