When manufacturing hardware for a telecommunications system, one of the basic tasks is to test the system for any production flaws. While there are many ways to test the hardware, one of the most popular methods uses the Joint Test Action Group (JTAG) boundary-scan method. The boundary-scan test method involves some minor changes to the hardware before production so that hardware verification can be performed after production. During design, all of the Integrated Circuit (IC) devices which support JTAG are connected in a serial daisy-chain fashion through the JTAG test access port. Verification is done by a specialized JTAG test system which connects to the test access port. The JTAG test system then uses a combination of the printed wiring board (PWB) netlist, Boundary-Scan Description Language (BSDL) files, and PWB connectivity test vectors to verify the pin-to-pin connections.

BSDL testing is straightforward. Nonetheless, multichip module devices like the DS33R41 Inverse-Multiplexing Ethernet Mapper with Integrated Quad Port T1/E1/J1 Transceiver cannot be properly described by a single BSDL file because there are multiple die in a single package. This shortcoming can be overcome with simple modification to the PWB netlist and by using two BSDL files to describe the device package instead of just one.

Before JTAG boundary scan testing can be performed, the portion of the PWB netlist that describes the external connections to the DS33R41 package must be modified to split those connections between the internal DS33Z41 die and DS21458 die. Once completed, the netlist will define the DS33R41 package with two independent reference designators. These reference designators allow two different BSDL files to individually describe the DS33Z41 and DS21458 connections inside the DS33R41 package.

Tables 1, 2, and 3 and Figure 1 make the task of modifying the netlist easy. Table 1 lists all of the external DS33R41 package pins which only connect to the DS33Z41 die. Table 2 lists all of the external DS33R41 package pins which only connect to the DS21458 die. Table 3 lists all of the external DS33R41 package pins which connect to both the DS33Z41 die and the DS21458 die. Figure 1 shows the same information in a format created for easier viewing.

This PWB netlist modification and JTAG boundary scan test have been performed using a Concise Net List format netlist of the DS33R41 engineering evaluation board designed with Cadence® Concept. Designers can perform the operation in approximately 30 to 60 minutes, depending on the netlist type and individual's skill level. Most of the edits to the netlist file can be done with a simple text editor. Depending on the netlist type, however, it may be possible to edit the netlist in a program such as Microsoft® Excel which can sort rows based on column data. However the editing is done, it is important to pay careful attention to detail. Irregular data such as header and footer information must be maintained, and the netlist must always be saved in the original format.

The following is a list of steps needed to complete the process.

1. Open the netlist file in a text editor and group all of the nets connected to the DS33R41 reference designator. As an example, the DS33R41 package on the DS33R41 Engineering Evaluation board had a reference designator of U01.
2. Separate all of the nets isolated in step 1 among those connected to the DS33Z41 die, those connected to the DS21458 die, and those connected to both dies. Use Tables 1, 2, and 3 and Figure 1 to complete this task.
3. Change the reference designator for all of the DS33Z41 nets from U01 to U01_D1 (short for reference designator U01, device 1). This step assumes that the DS33R41 reference designator was U01. If the reference designator is not U01, change U01_D1 appropriately.
4. Change the reference designator for all of the DS21458 nets from U01 to U01_D2 (short for reference designator U01, device 2). This assumes that the DS33R41 reference designator was U01. If it is not U01, change U01_D2 appropriately.
5. Duplicate the 22 shared nets so that there is exactly two of each. Split them into two groups.
6. Change the reference designator for first group of nets created in step 5 from U01 to U01_D1. This assumes that the DS33R41 reference designator was U01. If it is not U01, change U01_D1 appropriately.
7. Change the reference designator for second group of nets created in step 5 from U01 to U01_D2. This assumes that the DS33R41 reference designator was U01. If it is not U01, change U01_D1 appropriately.
8. Save the newly created netlist.

The newly created PCB netlist will actually contain two instances for the DS33R41 physical device. The first instance will describe the pin connections related to the DS33Z41 section; the second will describe pin connections related to the DS21458 section. The new netlist can be loaded into any JTAG test suite along with the two DS33R41 BSDL files and any associated test vectors.

Although the method documented here has been tested and verified to work properly, there can be some unforeseen complications with other netlist formats. If additional assistance is needed during JTAG boundary scan testing, please use the contact information below.

Table 1. Device Pins for DS33Z41 Die Only
Pin	Description		Pin	Description		Pin	Description
A1	VSS		J18	RXD[2]		P13	VSS
B16	VDD3.3		J19	RXD[0]		P14	SDMASK[1]
B17	VDD3.3		J20	VSS		P15	SRAS
B19	VDD3.3		K3	VSS		P16	SDA[11]
B20	VDD3.3		K5	VSS		P17	VDD1.8
C19	VDD3.3		K6	VSS		P18	SDMASK[2]
C20	REF_CLK		K7	VSS		P19	SDATA[18]
D10	VDD3.3		K8	VSS		P20	SDATA[19]
D15	VSS		K13	RMIIMIIS		R11	VSS
D18	VDD3.3		K14	TCLKE		R12	SDATA[12]
D19	VDD3.3		K15	TSERO		R13	SDATA[6]
D20	VDD3.3		K16	TBSYNC		R14	SCAS
E19	VDD3.3		K17	JTDI1		R15	SDCS
E20	MDC		K18	RX_DV		R16	SBA[0]
F11	VSS		K19	RX_CLK		R17	SDA[10]
F14	VSS		K20	RX_ERR		R18	SDATA[31]
F18	VDD3.3		L4	VSS		R19	VSS
F19	VDD3.3		L5	VSS		R20	VDD1.8
F20	MDIO		L6	VSS		T11	SDATA[13]
G4	VSS		L7	VSS		T12	SDATA[14]
G5	VSS		L8	VSS		T13	SDATA[5]
G7	VSS		L14	RCLKI		T14	VDD1.8
G12	VSS		L15	RBSYNC		T15	SWE
G13	JTMS1		L16	RSERI		T16	SDA[8]
G14	JTRST1		L17	DCEDTES		T17	SDA[0]
G15	MODEC[1]		L18	TX_CLK		T18	SDATA[16]
G16	VDD3.3		L19	TX_EN		T19	SDATA[27]
G18	QOVF		L20	TXD[0]		T20	SDATA[26]
G19	REF_CLKO		M5	VSS		U11	SDATA[15]
G20	VSS		M6	VSS		U12	SDATA[4]
H5	VSS		M7	VSS		U13	VSS
H6	VSS		M12	VSS		U14	SDCLKO
H7	VSS		M13	VDD1.8		U15	VSS
H8	VSS		M14	SDATA[3]		U16	SDA[1]
H9	VSS		M15	SDATA[1]		U17	SDA[4]
H10	VSS		M16	VSS		U18	SDATA[29]
H14	JTDO1		M17	VDD1.8		U19	SDATA[25]
H15	RST		M18	TXD[2]		U20	SDATA[24]
H16	CS		M19	TXD[1]		V11	SDATA[11]
H18	RXD[1]		M20	TXD[3]		V12	SDATA[10]
H19	RXD[3]		N12	VSS		V13	SDATA[8]
H20	VSS		N14	VDD1.8		V14	VSS
J6	VSS		N15	VDD1.8		V15	SDA[9]
J7	VSS		N16	VDD1.8		V16	SDA[7]
J8	VSS		N17	VDD1.8		V17	SDMASK[3]
J9	VSS		N18	VSS		V18	SDATA[30]
J15	VSS		N19	RX_CRS/CRS_DV		V19	SDATA[22]
J16	VDD1.8		N20	COL_DET		V20	VDD1.8
J17	JTCLK1		P12	VSS		W11	SDATA[0]
W12	SDATA[9]		W19	SDATA[20]		T16	SDA[6]
W13	SDATA[7]		W20	SDATA[23]		Y17	SDA[2]
W14	VDD1.8		Y11	SDATA[2]		Y18	VDD1.8
W15	SBA[1]		Y12	VSS		Y19	SDATA[28]
W16	SDA[5]		Y13	SDMASK[0]		Y20	SDATA[21]
W17	SDA[3]		Y14	SYSCLKI
W18	SDATA[17]		Y15	VDD1.8

Table 2. Device Pins for DS21458 Die Only
Pin	Description		Pin	Description		Pin	Description
A2	TSSYNC3		D3	TCHBLK3		G9	RNEGO2
A3	RMSYNC3		D4	RLOS/LOTC3		G10	DVSS
A4	RCHBLK3		D5	RSIG3		G11	DVSS
A5	RPOSO3		D6	TPD		G17	D0
A6	TSYSCLK3		D7	RNEGO3		H1	RCLK3
A9	TCLK2		D8	DVDD		H2	TSIG3
A10	TVDD		D9	DVDD		H3	DVSS
A11	TRING2		D11	DVDD		H4	TSYSCLK1
A12	TTIP2		D12	RCLKO2		H11	RSIG2
A13	TVSS		D13	TSYNC2		H12	RVSS
A14	TCHBLK2		D14	RCHCLK2		H13	RVSS
A15	RSYNC2		E1	TTIP3		J1	DVSS
B1	DVSS		E2	TTIP3		J2	TSERI3
B2	DVSS		E3	TCHCLK3		J3	TCLKT3
B3	RSYNC3		E5	RVSS		J4	DVDD
B4	RCHCLK3		E6	RTIP3		J5	TSYSCLK2
B5	RSERO3		E8	DVDD		J10	RPOSO2
B6	DVDD		E9	DVDD		J11	RVSS
B8	TSIG2		E10	DVDD		J12	RRING2
B9	TSERI2		E11	TCLKO2		J13	RTIP2
B10	TVDD		E12	TPOSO2		J14	RVDD
B11	TRING2		E13	TSSYNC2		K1	RSYSCLK1
B12	TTIP2		E14	RFSYNC2		K2	MCLK1
B13	TVSS		F1	TRING3		K4	RSERO1
B14	RCHBLK2		F2	TRING3		K9	RSERO2
C1	RCLKO3		F3	TNEGO3		K10	RSYSCLK2
C2	TSYNC3		F4	TPOSO3		L1	RVSS
C3	DVSS		F5	RVSS		L2	TRTRST
C4	RFSYNC3		F6	RRING3		L3	BPCLK1
C6	RSYSCLK3		F7	RVDD		L9	TCHCLK4
C7	JTDI2		F8	DVDD		L10	JTDO2
C8	RCLK2		F9	DVDD		L11	JTMS2
C9	DVDD		F10	DVDD		L12	MCLK2
C10	DVDD		F12	DVSS		L13	JTRST2
C11	DVDD		F13	RMSYNC2		M1	RRING1
C12	TNEGO2		G1	TVDD		M2	RVSS
C13	TCHCLK2		G2	DVDD		M3	RSIG1
C14	RLOS/LOTC2		G3	TCLKO3		M4	TCHBLK1
D1	TVSS		G6	RVSS		M8	RCHBLK4
D2	TVSS		G8	BPCLK2		M9	RSYNC4
M10	RFSYNC4		R5	DVSS		V6	RNEGO4
M11	TCLKO4		R6	DVSS		V7	RCHCLK4
N1	RTIP1		R7	TSERI4		V8	RLOS/LOTC4
N2	RVSS		R8	RVDD		V9	RMSYNC4
N3	RPOSO1		R9	RRING4		V10	DVSS
N4	RNEGO1		R10	RVSS		W1	TRING1
N5	DVSS		T1	TTIP1		W2	TVDD
N6	DVSS		T2	TVSS		W3	TSYNC1
N7	RCLK4		T3	DVSS		W4	TSSYNC1
N8	DVSS		T4	DVSS		W5	RCLK1
N9	TCLKT4		T5	DVSS		W6	CST
N10	TNEGO4		T6	DVSS		W7	TVSS
N11	TPOSO4		T7	RSERO4		W8	TTIP4
N13	TSSYNC4		T8	RVSS		W9	TRING4
P1	RVDD		T9	RTOP4		W10	TVDD
P2	RCHCLK1		T10	RVSS		Y1	RMSYNC1
P3	RCHBLK1		U1	TTIP1		Y2	RSYNC1
P4	TNEGO1		U2	TVSS		Y3	TCHCLK1
P5	DVSS		U4	TCLKT1		Y4	TSERI1
P6	TSYNC4		U5	DVSS		Y5	TSYSCLK4
P7	TSIG4		U6	DVSS		Y6	RSYSCLK4
P8	DVSS		U7	RPOSO4		Y7	TVSS
P9	JTCLK2		U8	RSIG4		Y8	TTIP4
P10	RCLKO4		U9	DVSS		Y9	TRING4
P11	TCHBLK4		U10	DVSS		Y10	TVDD
R1	RFSYNC1		V1	TRING1
R2	RLOS/LOTC1		V2	TVDD
R3	TPOSO1		V4	RCLKO1
R4	TCLKO1		V5	TSIG1

Table 3. Shared Device Pins for DS33Z41 and DS21458 Die
Pin	Description		Pin	Description		Pin	Description
A16	WR/RW		C16	A9		E17	A6
A17	D1		C17	A7		E18	A4
A18	A5		C18	A2		F15	RD/DS
A19	A0		D16	D5		F16	D3
A20	A1		D17	A8		F17	D2
B15	D6		E7	MODEC[0]		G17	D0
B18	A3		E15	INT
C15	D7		E16	D4

More Detailed Image (PDF, 237kB)
Figure 1. DS33R41 400-ball BGA, color-coded pinout and die map.

If you have additional questions on the JTAG testing of the DS33R41, please contact the Telecommunication Applications support team.

For more information about the DS33R41 Inverse-Multiplexing Ethernet Mapper with Integrated Quad Port T1/E1/J1 Transceiver, please consult the appropriate data sheet at: T/E Carrier and Packetized Communications.