23
OUTPUT ENABLE CONNECTION
•
Pin 24
is the output enable active low input used to control the logical state of the data lines. When this pin is HIGH, the
data lines are in the high impedance condition and no data is present on these pins. When the output enable input it LOW,
the data lines are active and output the addressed data, This line is connected to the data strobe output of the
microcontroller to ensure correct operation/timings.
CHIP ENABLE CONNECTION
•
Pin 22
is the chip enable active low input used to select the device. Normally, this input is low to enable the device.
However, the device can be placed in a standby state when accessing a future SRAM in position I003. The MMU3 line
from the microcontroller is used to select either the SRAM or the MTP. When no SRAM is fitted, the chip enable pin is
always low.
MISCELLANEOUS
•
Pin 1
(VPP) is the programming voltage input pin (+12.75V needed) used to re-program the device when placed in a
special programmer. This pin is always tied to the +5V standby supply, to ensure that the device can never be re-
programmed inside the television chassis.
•
Pin 30
is not used in this device. However, it is still connected to the MMU1 line from the microcontroller for use with
larger size MTP’s/EPROM’s. This line can be used to access a further 128Kbytes if such a device was fitted.
•
Pin 31
is the active-low programming enable pin that is used to re-program and erase the device. This pin is always
connected to the +5V standby supply to ensure that no inadvertent writes/erases are performed on the device.
SRAM (I003)
INTRODUCTION
On future chassis, the position I003 will be used to hold an SRAM for teletext page storage and memory storage. A 128Kbyte device
will most likely be situated here to allow 100 teletext pages to be acquired and stored for immediate fast access to them. The SRAM
is connected to the microcontroller’s address and data lines, which are shared with the EPROM/MTP in position I002.
DESCRIPTION
SUPPLY/GROUND CONNECTIONS
•
Pins 32
and
16
are the +5V supply and ground connections respectively. This device always has +5V connected to it,
even when the TV is in the standby state.
ADDRESS LINE CONNECTIONS
•
Pins 2
to
12, 23, 31
and
25
to
28
are the address lines needed to access the 128Kbyte of data by the microcontroller.
DATA LINE CONNECTIONS
•
Pins 13
to
15
and
17
to
21
are the 8-bit data lines needed to receive/transmit a byte of data at a time to/from the
microcontroller.
CHIP ENABLE CONNECTIONS
•
Pins 22
and
30
are 2 chip enable inputs that need to be LOW and HIGH respectively for the 128Kbyte device to operate.
If either pin 22 is HIGH or pin 30 is LOW, then the device enters a standby state whereby its power consumption is
dramatically reduced (10uW). The MMU3 output pin from the microcontroller (pin 2) is used to select the SRAM when it is
HIGH. If this pin is low, then the MTP/EPROM in position I002 is selected instead.
WRITE ENABLE CONNECTIONS
•
Pin 29
is the active-low write enable input used to enable data to be stored inside the device. This pin is connected to the
read/write line of the microcontroller for synchronisation purposes.
74HC04 HEX INVERTER (I004)
INTRODUCTION
The 14-pin IC in position I004 is a high speed CMOS hex inverter used to invert digital signals. The package consists of 6 inverters,
but only 4 are used in this application.
DESCRIPTION
SUPPLY/GROUND CONNECTIONS
•
Pins 14
and
7
are the +5V and 0V supply connections respectively. This device always has +5V supplied to it, even when
the TV is in the standby state. Capacitor C023 is connected across the supply terminal for de-coupling.
CHIP ENABLE CONNECTION
•
Pin 1
is connected to the MMU3 output from the microcontroller and is used to select either the MTP or the SRAM. This
signal is inverted and output from pin 2 that is then connected to the active low chip enable input (pin 22) of the SRAM. In
this way, only one chip enable line from the microcontroller needs to be used to enable the SRAM.
Содержание C28W40TN
Страница 29: ...28 GENERAL BLOCK DIAGRAM ...
Страница 91: ...90 CASE DE FONCTIONS EXTRÉMITÉ HAUTE CASE FONCTIONS EXTRÉMITÉ BASSE ...
Страница 102: ...101 SCHÉMA SYNOPTIQUE ...
Страница 165: ...164 HÖHERE FEATURE BOX NIEDRIGE FEATURE BOX ...
Страница 177: ...176 BLOCKSCHALTBILD ...
Страница 200: ...199 ...
Страница 225: ...224 WAVEFORMS ...
Страница 226: ...225 ...
Страница 227: ...226 ...
Страница 228: ...227 ...
Страница 229: ...228 ...
Страница 230: ...229 IC DATA I200 ...
Страница 231: ...230 ...
Страница 232: ...231 ...
Страница 233: ...232 IE01 ...
Страница 234: ...233 ...
Страница 235: ...234 IE02 ...
Страница 236: ...235 ...
Страница 237: ...236 ...
Страница 238: ...237 MECHANICAL ...
Страница 239: ...239 C32W35TN ...
Страница 240: ...240 C32W35TN ...
Страница 241: ...241 C32W35TN ...
Страница 242: ...242 CL28W35TAN ...
Страница 243: ...243 CL28W35TAN ...
Страница 244: ...244 CL28W35TAN ...
Страница 245: ...245 CL32W35TAN ...
Страница 246: ...246 CL32W5TAN ...
Страница 247: ...247 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 248: ...248 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 249: ...249 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 250: ...250 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 251: ...251 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 252: ...252 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 253: ...253 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 254: ...254 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 255: ...255 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 256: ...256 C28W40TN C32W40TN ...
Страница 257: ...257 C28W40TN C32W40TN ...
Страница 258: ...258 C28W40TN C32W40TN ...
Страница 259: ...259 C28W40TN C32W40TN ...
Страница 260: ...260 C28W40TN C32W40TN ...
Страница 261: ...261 C28W40TN C32W40TN ...
Страница 262: ...262 C28W40TN C32W40TN ...
Страница 263: ...263 C28W40TN C32W40TN C28W40TN C32W40TN ...
Страница 264: ...264 C28W40TN C32W40TN ...
Страница 265: ...265 C28W40TN C32W40TN ...
Страница 266: ...266 C28W40TN C32W40TN ...
Страница 267: ...267 C28W40TN C32W40TN ...
Страница 268: ...268 C28W40TN C32W40TN ...
Страница 269: ...269 C28W40TN C32W40TN ...
Страница 270: ...270 C28W40TN C32W40TN ...
Страница 271: ...271 C28W40TN C32W40TN ...
Страница 272: ...272 C28W40TN C32W40TN ...
Страница 273: ...273 C28W40TN C32W40TN ...
Страница 274: ...274 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 275: ...275 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 276: ...276 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 277: ...277 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 278: ...278 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 279: ...279 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 280: ...280 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 281: ...281 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 282: ...282 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 283: ...283 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 284: ...284 C35W35TN CL28W35TAN CL32W5TAN ...
Страница 285: ...285 C28W40TN C32W40TN ...
Страница 286: ...286 C28W40TN C32W40TN ...
Страница 287: ...287 C28W40TN C32W40TN ...
Страница 288: ...288 C28W40TN C32W40TN ...
Страница 289: ...289 C28W40TN C32W40TN ...
Страница 290: ...290 C28W40TN C32W40TN ...
Страница 291: ...291 C28W40TN C32W40TN ...
Страница 292: ...292 C28W40TN C32W40TN ...
Страница 293: ...293 C28W40TN C32W40TN ...
Страница 294: ...294 C28W40TN C32W40TN ...
Страница 295: ...295 C28W40TN C32W40TN ...
Страница 296: ...296 C28W40TN C32W40TN ...
Страница 297: ......
Страница 299: ...Users Guide C28W40TN C32W40TN ...
Страница 351: ...notes ...
Страница 352: ...notes ...
Страница 353: ...notes ...
Страница 355: ...Users Guide C28W35TN C32W35TN S C R E E N S C R E E N ...