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Freescale Semiconductor
35-1
Chapter 35
IEEE 1149.1 Test Access Port (JTAG)
35.1
Introduction
The Joint Test Action Group (JTAG) is a dedicated user-accessible test logic compliant with the
IEEE 1149.1 standard for boundary-scan testability, which helps with system diagnostic and
manufacturing testing.
This architecture provides access to all data and chip control pins from the board-edge connector through
the standard four-pin test access port (TAP) and the JTAG reset pin, TRST.
35.1.1
Block Diagram
shows the block diagram of the JTAG module.
Figure 35-1. JTAG Block Diagram
TDO/DSO
BKPT
5-bit TAP Instruction Register
4
0
1-bit Bypass Register
32-bit IDCODE Register
TRST/DSCLK
TCLK
TMS/BKPT
0
31
TAP Controller
TDI/DSI
1
0
JTAG Module
to Debug Module
5-bit TAP Instruction Decoder
1
0
Disable DSCLK
Force BKPT = 1
DSI = 0
JTAG_EN
DSO
DSI
DSCLK
1-bit TEST_CTRL Register
Boundary Scan Register
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
Page 601: ...Freescale Semiconductor 1 ...
Page 842: ...I2 C Interface Freescale Semiconductor 33 16 ...
Page 843: ...Freescale Semiconductor 1 ...
Page 921: ...Revision History A 6 Freescale Semiconductor ...