3 \author Dave Huseby <huseby at linuxprogrammer.org>
4 \brief Intel XScale JTAG
7 /* NOTE: I heavily cribbed from the ARM7TDMI jtag implementation. Credit where
15 #define JTAGXSCALE 0x15
18 * XScale 5-bit JTAG Commands
21 /* On the XScale chip, the TDI pin is connected to the MSB of the IR and the
22 * TDO is connected to the LSB. That means we have to shift these commands
23 * in from LSB to MSB order. */
26 * The highz instruction floats all three-stateable output and in/out pins.
27 * Also, when this instruction is active, the Bypass register is connected
28 * between TDI and TDO. This register can be accessed via the JTAG Test-Access
29 * Port throughout the device operation. Access to the Bypass register can also
30 * be obtained with the bypass instruction. */
31 #define XSCALE_IR_HIGHZ 0x08
33 /* 11110 - Get ID Code
34 * The idcode instruction is used in conjunction with the device identification
35 * register. It connects the identification register between TDI and TDO in the
36 * Shift_DR state. When selected, idcode parallel-loads the hard-wired
37 * identification code (32 bits) on TDO into the identification register on the
38 * rising edge of TCK in the Capture_DR state. Note: The device identification
39 * register is not altered by data being shifted in on TDI.*/
40 #define XSCALE_IR_IDCODE 0x1E
43 * The bypass instruction selects the Bypass register between TDI and TDO pins
44 * while in SHIFT_DR state, effectively bypassing the processor’s test logic.
45 * 02 is captured in the CAPTURE_DR state. While this instruction is in effect,
46 * all other test data registers have no effect on the operation of the system.
47 * Test data registers with both test and system functionality perform their
48 * system functions when this instruction is selected. */
49 #define XSCALE_IR_BYPASS 0x1F
52 * GoodFET Commands from the Client
54 /* commands start at 0xF0 */
61 /* this handles shifting arbitrary length bit strings into the instruction
62 * register and clocking out bits while leaving the JTAG state machine in a
63 * known state. it also handle bit swapping. */
64 unsigned long jtag_xscale_shift_n(unsigned long word,
68 extern app_t const jtagxscale_app;
70 #endif // JTAGXSCALE_H