CY7C0850AV/CY7C0851AV
CY7C0852AV/CY7C0853AV
Document #: 38-06070 Rev. *G
Page 11 of 31
IEEE 1149.1 Serial Boundary Scan (JTAG)[13]
The CY7C0850AV/CY7C0851AV/CY7C0852AV/CY7C0853AV
incorporates an IEEE 1149.1 serial boundary scan test access
port (TAP). The TAP controller functions in a manner that does
not conflict with the operation of other devices using
1149.1-compliant
TAPs.
The
TAP
operates
using
JEDEC-standard 3.3V I/O logic levels. It is composed of three
input connections and one output connection required by the
test logic defined by the standard.
Performing a TAP Reset
A reset is performed by forcing TMS HIGH (VDD) for five rising
edges of TCK. This reset does not affect the operation of the
devices, and may be performed while the devices are
operating. An MRST must be performed on the devices after
power-up.
Performing a Pause/Restart
When a SHIFT-DR PAUSE-DR SHIFT-DR is performed the
scan chain will output the next bit in the chain twice. For
example, if the value expected from the chain is 1010101, the
device will output a 11010101. This extra bit will cause some
testers to report an erroneous failure for the devices in a scan
test. Therefore the tester should be configured to never enter
the PAUSE-DR state.
216 215
26
21
25
22
24 23
20
216 215
26
21
25
22
24 23
20
216 215
26
21
25
22
24 23
20
216 215
26
21
25
22
24 23
20
H
H
L
H
11
0s
1
0
1
0
1
01
00
Xs
1
X
0
X
0
X0
11
Xs
1
X
1
X
1
X1
00
Xs
1
X
0
X
0
X0
Masked Address
Unmasked Address
Mask
Register
bit-0
Address
Counter
bit-0
CNTINT
Example:
Load
Counter-Mask
Register = 3F
Load
Address
Counter = 8
Max
Address
Register
Max + 1
Address
Register
Figure 2. Programmable Counter-Mask Register Operation[1, 12]
Table 4. Identification Register Definitions
Instruction Field
Value
Description
Revision Number (31:28)
0h
Reserved for version number.
Cypress Device ID (27:12)
C001h
Defines Cypress part number for the CY7C0851AV
C002h
Defines Cypress part number for the CY7C0852AV and CY7C0853AV
C092h
Defines Cypress part number for the CY7C0850AV
Cypress JEDEC ID (11:1)
034h
Allows unique identification of the DP family device vendor.
ID Register Presence (0)
1
Indicates the presence of an ID register.
Notes:
12. The “X” in this diagram represents the counter upper bits.
13. Boundary scan is IEEE 1149.1-compatible. See “Performing a Pause/Restart” for deviation from strict 1149.1 compliance