DataSheet.jp

UM6845RB の電気的特性と機能

UM6845RBのメーカーはUMCです、この部品の機能は「CRT Controller」です。


製品の詳細 ( Datasheet PDF )

部品番号 UM6845RB
部品説明 CRT Controller
メーカ UMC
ロゴ UMC ロゴ 




このページの下部にプレビューとUM6845RBダウンロード(pdfファイル)リンクがあります。
Total 13 pages

No Preview Available !

UM6845RB Datasheet, UM6845RB PDF,ピン配置, 機能
·@)UMC
UM6845R/UM6845RA/UM6845RB
==::::====::::==::::::::::::::::CRT Conuoner
Features
• Single + 5 volt (±5%) power supply
• Alphanumeric and limited graphics capabilities
• Fully programmable display (rows, columns, blanking,
etc.)
• Interlaced or non-interlaced scan
• 50/60 Hz operation
• Fully programmable cursor
• External light pen capability
• Capable of addressing up to 16K character Video Display
RAM.
• No DMA required
• Compatible with SY6845R
• Straight-binary addressing for Video Display RAM
General Description
The UM6845R is a CRT Controller intended to provide
capability for interfacing any microprocessor family to
CRT or TV-type raster scan displays. A unique feature
is the inclusion of several modes of operation, so that the
system designer can configure the system with a wide
assortment of techniques.
Pin Configuration
GND
RES
LPEN
CCO/MAO
CC1/MA1
CC2/MA2
CC3/MA3
CC4/MA4
CC5/MA5
CC6/MA6
CC7/MA7
CRO/MA8
CR1/MA9
CR2/MA10
CR3/MA11
CR4/MA12
CR5/MA13
DISPLAY ENABLE
CURSOR
Vce
Block Diagram
VSYNC
HSYNC
RAO
RA1
RA2
RA3
RA4
DBO
DB1
DB2
DB3
DB4
DB5
DB6
DB7
CS
RS
E
R/W
CCLK
VCC GND
DBO-DB7
HSYNC
1 - - - - VSYNC
t---- DISPLAY ENABLE
R/!-~-+I UM6845R CRTC
CURSOR
t _ _ - - LPEN
CS ....._ _ CCLK
RS t _ _ - - RES
MAO-MA13 RAO-RA4
\{
VIDEO D.lSPLAY RAM AND CHARACTER RoM
5-26

1 Page





UM6845RB pdf, ピン配列
A.C. Electrical Characteristics
MPU BUS INFERFACE CHARACTERISTICS
WRITE CYCLE
E _ _ _J
RS
CS, R/W
OATA BUS
UM6845R / UM6845RA / UM6845RB
READ CYCLE
E
RS
CS, R/Iii
OATA BUS
WRITE TIMING CHARACTERISTICS (Vcc = 5.0V ± 5%, TA = 0 - 70°C, unless otherwise noted)
Symbol
Characteristics
tCYC
Cycle Time
PWEH
E Pulse Width, High
PWEL
E Pulse Width, Low
tAS Address Set-Up Time
tAH Address Hold Time
tcs R/W, CS Set-Up Time
tCH R/W, CS Hold Time
tosw
Data Bus Set-Up Time
tOHW
Data Bus Hold Time
(tr and tf = 10 to 30 ns)
UM6845R
Min. Max.
1.0 -
440 -
420 -
80 -
0-
80 -
0-
165 -
10 -
UM6845RA
Min. Max.
0.5 -
200 -
190 -
40 -
0-
40 -
0-
60 -
10 -
UM6845RB
Min. Max.
0.33
-
150 -
140 -
30 -
0-
30 -
0-
60 -
10 -
READ TIMING CHARACTERISTICS. (Vcc = 5.0V ± 5%, TA = 0 - 70°C, unless otherwise noted)
Symbol
Characteristics
tCYC
Cycle Time
PWEH
E Pulse Width, High
PWEL
E Pulse Width, Low
tAS Address Set-Up Time
tAH Address Hold Time
tcs R/W, CS Set-Up Time
tooR
Read Access Time (Valid Data)
tOHR
Read Hold Time
tOA Data Bus Active Time (Invalid Data)
(tr and tf = 10 to 30 ns)
UM6845R
Min.
1.0
Max.
-
440 -
420 -
80 -
0-
80 -
- 290
20 60
40 -
UM6845RA
Min. Max.
0.5 -
200 -
190 -
40 -
0-
40 -
- 150
20 60
40 -
UM6845RB
Min. Max.
0.33 -
150 -
140 -
30 -
0-
30 -
- 100
20 60
40 -
Units
/-ls
ns
ns
ns
ns
ns
ns
ns
ns
Units
/-ls
ns
ns
ns
ns
ns
ns
ns
ns
5-28


3Pages


UM6845RB 電子部品, 半導体
UM6845R / UM6845RA / UM6845RB
RAO-RA4 (Raster Address Lines)
These signals are active-high outputs and are used to select
each raster scan within an individual character row. The
number of raster scan lines is programmable and determines
the character height, including spaces between character
rows.
I SCAN
] LINES
Horizontal Total (RO)
This 8-bit register contains the total of displayed and
non-displayed characters, minus one, per horizontal line.
The frequency of HSYNC is thus determined by this
register.
Horizontal Displayed (R1)
This 8-bit register contains the number of displayed
characters per horizontal line.
VERT
J 191C~T
NUM8EROF
SCAN LINES
PER
CHARACTER
ROW
Horizontal Sync Position (R2)
This 8-bit register contains the position of the HSY NC on
the horizontal line, in terms of the character location
number on the line. The position of the HSYNC deter-
mines the left-to-right location of· the displayed text on
the video screen. In this way, the side margins are adjusted.
Figure 1. Video Display Format
Horizontal and Vertical SYNC Widths (R3)
This 4-bit register programs the width of HSYNC.
Description of Internal Registers
Figure 1 illustrates the format of a typical video display
and is necessary to understand the functions of the various
UM6845R Internal registers. Figure 2 illustrates vertical
and horizontal timing. Figure 3 summarizes the internal
registers and ind icates their address selection and read/
write capabilities.
Address Register
This is a 5-bit register which is used as a "pointer" to
direct UM6845R data transfers to and from the system
MPU. Its contents is the number of the desired register
(0-31). When RS is low, then this register may be loaded;
when RS is high, then the register selected is the one
whose identity is stored in this register.
Status Register
This 2-bit register is used tt monitor the status of the
CRTC, as follows:
765 432
0
,8'--4--.2I-----1,
HSYNC WIDTH
I
(NUMBER OF
CHARACTER CLOCK
TIMES)
VSYNC width is set to 16 scan line times.
Vertical Total (R4)
The Vertical Total Register is a 7-bit register containing
the total number of character rows in a frame, minus one.
This register, along with R5, determines the overall frame
rate, which should be close to the line frequency to ensure
flicker-free appe~rance. If the frame time is adjusted to
be longer than the period of the line frequency, then RES
may be used to provide absolute synchronism.
7 6 5 4 320
IL LNOTUSEQJVERTICAL BLANKING
"0" Scan currently not in vertical blanking
portion of its timing.
"1" Scan currently is in its vertical blanking
time.
L--_ _ _ LPEN REGISTER FULL
"0" This bit goes to "0" whenever either
register R16 or R17 is read by the MPU.
"1" This bit goes to "1" whenever a LPEN
strobe occurs.
~----- NOT USED
Vertical Total Adjust (R5)
The Vertical Total Adjust Register is a 5-bit write only
register containing the number of additional scan lines
needed to complete an entire frame scan and is intended
as a fine adjustment for the video frame time.
Vertical Displayed (R6)
This 7-bit register contains the number of displayed
character rows in each frame. In this way, the vertical
size of the displayed text is determined.
Vertical Sync Position (R7)
This 7-bit register is used to select the character row time
at which the VSYNC pulse is desired to occur and, thus,
is used to position the displayed text in the vertical direc-
tion.
5-31

6 Page



ページ 合計 : 13 ページ
 
PDF
ダウンロード
[ UM6845RB データシート.PDF ]


データシートを活用すると、その部品の主な機能と仕様を詳しく理解できます。 ピン構成、電気的特性、動作パラメータ、性能を確認してください。


共有リンク

Link :


部品番号部品説明メーカ
UM6845R

CRT Controller

UMC
UMC
UM6845RA

CRT Controller

UMC
UMC
UM6845RB

CRT Controller

UMC
UMC


www.DataSheet.jp    |   2020   |  メール    |   最新    |   Sitemap