CY8C32_12 CYPRESS [Cypress Semiconductor], CY8C32_12 Datasheet - Page 62

• Manufacturer Part Number: CY8C32_12
• Manufacturer: CYPRESS [Cypress Semiconductor]

9.3 Debug Features
Using the JTAG or SWD interface, the CY8C32 supports the
following debug features:
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9.4 Trace Features
The CY8C32 supports the following trace features when using
JTAG or SWD:
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9.5 Single Wire Viewer Interface
The SWV interface is closely associated with SWD but can also
be used independently. SWV data is output on the JTAG
interface’s TDO pin. If using SWV, you must configure the device
for SWD, not JTAG. SWV is not supported with the JTAG
interface.
SWV is ideal for application debug where it is helpful for the
firmware to output data similar to 'printf' debugging on PCs. The
SWV is ideal for data monitoring, because it requires only a
single pin and can output data in standard UART format or
Manchester encoded format. For example, it can be used to tune
a PID control loop in which the output and graphing of the three
error terms greatly simplifies coefficient tuning.
The following features are supported in SWV:
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9.6 Programming Features
The JTAG and SWD interfaces provide full programming
support. The entire device can be erased, programmed, and
verified. You can increase flash protection levels to protect
firmware IP. Flash protection can only be reset after a full device
Document Number: 001-56955 Rev. *N
Halt and single-step the CPU
View and change CPU and peripheral registers, and RAM
addresses
Eight program address breakpoints
One memory access breakpoint—break on reading or writing
any memory address and data value
Break on a sequence of breakpoints (non recursive)
Debugging at the full speed of the CPU
Compatible with PSoC Creator and MiniProg3 programmer and
debugger
Standard JTAG programming and debugging interfaces make
CY8C32 compatible with other popular third-party tools (for
example, ARM / Keil)
Trace the 8051 program counter (PC), accumulator register
(ACC), and one SFR / 8051 core RAM register
Trace depth up to 1000 instructions if all registers are traced,
or 2000 instructions if only the PC is traced (on devices that
include trace memory)
Program address trigger to start tracing
Trace windowing, that is, only trace when the PC is within a
given range
Two modes for handling trace buffer full: continuous (overwriting
the oldest trace data) or break when trace buffer is full
32 virtual channels, each 32 bits long
Simple, efficient packing and serializing protocol
Supports standard UART format (N81)
erase. Individual flash blocks can be erased, programmed, and
verified, if block security settings permit.
9.7 Device Security
PSoC 3 offers an advanced security feature called device
security, which permanently disables all test, programming, and
debug ports, protecting your application from external access.
The device security is activated by programming a 32-bit key
(0×50536F43) to a Write Once Latch (WOL).
The Write Once Latch is a type of nonvolatile latch (NVL). The
cell itself is an NVL with additional logic wrapped around it. Each
WOL device contains four bytes (32 bits) of data. The wrapper
outputs a ‘1’ if a super-majority (28 of 32) of its bits match a
pre-determined pattern (0×50536F43); it outputs a ‘0’ if this
majority is not reached. When the output is 1, the Write Once NV
latch locks the part out of Debug and Test modes; it also
permanently gates off the ability to erase or alter the contents of
the latch. Matching all bits is intentionally not required, so that
single (or few) bit failures do not deassert the WOL output. The
state of the NVL bits after wafer processing is truly random with
no tendency toward 1 or 0.
The WOL only locks the part after the correct 32-bit key
(0×50536F43) is loaded into the NVL's volatile memory,
programmed into the NVL's nonvolatile cells, and the part is
reset. The output of the WOL is only sampled on reset and used
to disable the access. This precaution prevents anyone from
reading, erasing, or altering the contents of the internal memory.
The user can write the key into the WOL to lock out external
access only if no flash protection is set (see
page 22). However, after setting the values in the WOL, a user
still has access to the part until it is reset. Therefore, a user can
write the key into the WOL, program the flash protection data,
and then reset the part to lock it.
If the device is protected with a WOL setting, Cypress cannot
perform failure analysis and, therefore, cannot accept RMAs
from customers. The WOL can be read out via SWD port to
electrically identify protected parts. The user can write the key in
WOL to lock out external access only if no flash protection is set.
For more information on how to take full advantage of the
security features in PSoC see the PSoC 3 TRM.
Disclaimer
Note the following details of the flash code protection features on
Cypress devices.
Cypress products meet the specifications contained in their
particular Cypress datasheets. Cypress believes that its family of
products is one of the most secure families of its kind on the
market today, regardless of how they are used. There may be
methods, unknown to Cypress, that can breach the code
protection features. Any of these methods, to our knowledge,
would be dishonest and possibly illegal. Neither Cypress nor any
other semiconductor manufacturer can guarantee the security of
their code. Code protection does not mean that we are
guaranteeing the product as “unbreakable.”
Cypress is willing to work with the customer who is concerned
about the integrity of their code. Code protection is constantly
evolving. We at Cypress are committed to continuously
improving the code protection features of our products.
PSoC
®
3: CY8C32 Family
“Flash Security”
Data Sheet
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