13. JTAG
139
Tsi384 User Manual
May 5, 2014
Integrated Device Technology
www.idt.com
13.6
JTAG Register Access
The JTAG Interface can be used for debug purposes in order to perform read and write access of the
Tsi384’s configuration registers. It also can perform read accesses on the performance registers without
impacting active transactions.
A user-defined command enables the read and write capabilities of the JTAG Interface. This is in the
User Test Data Register (DR) set in the Tsi384.
13.6.1
Register Access from JTAG
The format for access the Tsi384’s DR register using JTAG is shown in the following figures. The same
DR register is used for read and write access.
Figure 38: Read/Write Access from JTAG — Serial Data In
Figure 39: Observe from JTAG — Serial Data Out
13.6.2
Write Access to Registers from the JTAG Interface
Complete the following steps to write to a device register through the JTAG Interface:
1.
Move to the TAP controller “Shift-IR” state and program the instruction register with the
instruction of the DR by writing into Instruction Register bits with 0x3F_FFFF_FFFF_FFFD.
2.
Move to the “Shift-DR” state and shift the data[31:0], R/W = 1 and the address[9:0] serially in the
TDI pin. To prevent corruption of unused bits, the full DR bits have to be written as follows (see
also
•
DR[68:64] = 5b’0
•
DR[63:54] = ADDR[9:0]
1
•
DR[53] = R/W
•
DR[52:21] = DATA[31:0]
•
DR[20:19] = 2b’0
Ti
p
For more information about the test data register, see Test Technology Standards Committee:
IEEE Computer Society,
IEEE Standard Test Access Port and Boundary-Scan Architecture
,
IEEE Std. 1149.1-1990, 1149.1a-1993, October, 1993., Section 8.3.
1. Note that the address here is the DWORD address, not the byte address. Take the byte address and remove the 2 LSBs, >>2.
JTAG_TDI
JTAG_TDO
Address [9:0]
R/W
Ready
Error
Data [31:0]
Rsvd [18:0]
Reserved [68:64]
JTAG_TDI
JTAG_TDO
Data [31:0] Error
Reserved [68:34]
Ready
Содержание TSI384
Страница 1: ... IDT Tsi384 PCIe to PCI Bridge User Manual May 5 2014 ...
Страница 10: ...Contents 10 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 36: ...2 Signal Descriptions 36 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 56: ...4 Addressing 56 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 62: ...5 Configuration Transactions 62 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 74: ...6 Bridging 74 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 78: ...7 PCI X Arbitration 78 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 128: ...11 Power Management 128 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 136: ...12 Serial EEPROM 136 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 142: ...13 JTAG 142 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 268: ...16 Packaging 268 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 276: ...276 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...
Страница 280: ...Index 280 Tsi384 User Manual May 5 2014 Integrated Device Technology www idt com ...