TA235 ST Microelectronics, Inc., TA235 Datasheet - Page 3

• Manufacturer Part Number: TA235
• Description: Technical Article
• Manufacturer: ST Microelectronics, Inc.

The software protection is a register based read
and write protection in FWH interface mode. The
registers can be altered to set the appropriate
Locking to protect against piracy. Depending on
the degree of protection required, the Lock
Registers can set the memory in either Read Lock,
Write Lock or Lock Down mode .
The Firmware Hub protocol is Intel proprietary and
is based on the Low Pin Count Interface (LPC).
Four Signal Communication pins (FWH0 – FWH3)
together with an Input Communication Frame
(FWH4) are used to determine the bus operation.
A four bit Cycle Type (CYCLETYPE) defines
whether it is Reading or Writing to the FWH.
The Device Select bits (IDSEL) indicate which
FWH device is selected. The Memory Size Cycle
(MSIZE) always gives 0000 (single byte transfer).
The Turn Around bits (TAR), occupying two clock
cycles, are driven by the host when it is turning
control over to the peripheral and driven by the
peripheral when it is turning control over to the
host. Synchronize bits (SYNC) are required to
Figure 5. Address/Address Multiplexed Interface Read Protocol
A0-A10
RC
G
DQ0-DQ7
W
RP
tAVCL
ROW ADDR VALID
tPHAV
tCLAX
COLUMN ADDR VALID
tAVAV
tAVCH
bring the chip-sets into synchronization. Figure 2
shows the Firmware Hub Read Protocol and
Figure 3 shows the Firmware Hub Write Protocol.
Address/Address Multiplexed Interface
The
features:
Figure 4 shows the pin description for A/A Mux
interface mode.
tGLQV
tGLQX
11 Address Inputs for Row/Column
addressing,
8 Data Inputs/Outputs for data bus operation,
Output Enable for Read operation,
Write Enable for Programming operation,
Row/Column Address Select (RC) for Row or
Column Address Latch
Ready/Busy Output for verify operation.
tCHQV
tCHAX
Address/Address
NEXT ADDR VALID
tGHQX
tGHQZ
VALID
Multiplexed
AI03406
Interface
TA 235
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