Jtag Control Signal Register For 1Xx/2Xx/4Xx Families - Texas Instruments MSP430 User Manual

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Note: IR_DATA_QUICK cannot be used on flash memory.
8.2.4.2.4 IR_BYPASS
This instruction delivers the input to TDI as an output on TDO delayed by one TCK clock. When this
instruction is loaded, the IR_CNTRL_SIG_RELEASE instruction, which is defined in the following section,
is performed simultaneously. After execution of the bypass instruction, the 16-bit data shifted out on TDI
does not affect any register of the target MSP430's JTAG control module.
8.2.4.3 Controlling the CPU
The following instructions enable control of the MSP430 CPU through a 16-bit register accessed via
JTAG. This data register is called the JTAG control signal register.
making up the JTAG control signal register used for memory access.
Bit No. Name
0 R/W
1 (N/A)
2 (N/A)
3 HALT_JTAG
4 BYTE
5 (N/A)
6 (N/A)
7 INSTR_LOAD
8 (N/A)
9 TCE
10 TCE1
11 POR
12 Release low byte
13 TAGFUNCSAT
14 SWITCH
15 (N/A)
SLAU265 – February 2009
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Table 8-5. JTAG Control Signal Register for 1xx/2xx/4xx Families
Controls the read/write (RW) signal of the CPU
1 = Read
0 = Write
Always write 0
Always write 0
Sets the CPU into a controlled halt state
1 = CPU stopped
0 = CPU operating normally
Controls the BYTE signal of the CPU used for memory access data length
1 = Byte (8-bit) access
0 = Word (16-bit) access
Always write 0
Always write 0
Read only: Indicates the target CPU instruction state
1 = Instruction fetch state
0 = Instruction execution state
Always write 0
Indicates CPU synchronization
1 = Synchronized
0 = Not synchronized
Establishes JTAG control over the CPU
1 = CPU under JTAG control
0 = CPU free running
Controls the power-on-reset (POR) signal
1 = Perform POR
0 = No reset
Selects control source of the RW and BYTE bits
1 = CPU has control
0 = Control signal register has control
Sets flash module into JTAG access mode
1 = CPU has control (default)
0 = JTAG has control
Enables TDO output as TDI input
1 = JTAG has control
0 = Normal operation
Always write 0
Interface and Instructions
Table 8-5 describes the bit functions
Description
MSP430 Programming Via the JTAG Interface 63