MAC7200 datasheet(262/976 Pages) FREESCALE

262 / 976 page

Functional Description

MAC7200 Microcontroller Family Reference Manual, Rev. 2

184

Freescale Semiconductor

11.11.4.5 Watchpoint Timing Diagram (2 MDO / 1 MSEO configuration)

Figure 11-48. Watchpoint Message & Watchpoint Error Message

11.11.5 Read/Write Access

The Read/Write access feature allows access to internal memory mapped resources via the JTAG port. The

Read/Write mechanism supports single as well as block reads and writes via an AHB system bus.

11.11.5.1 Functional Description

The Nexus3 module includes the capability of accessing resources on the AHB. All accesses are setup and

initiated by the Read/Write Access Control/Status Register (RWCS), as well as the Read/Write Access

Address (RWA) and Read/Write Access Data Registers (RWD).

11.11.5.2 Read/Write Access to Internal Nexus Registers

Access to Nexus register resources is enabled by loading a single instruction (“NEXUS-ACCESS”) into the

JTAG Instruction Register (IR). For the A7S Nexus3 block, the JTAG IR value is programmable at the

platform or SOC integration level. It can be programmed to any of the non-ARM7 implemented IR values

(see Table 11-35).

Once the JTAG “NEXUS-ACCESS” instruction has been loaded, the JTAG port allows communication

with all Nexus registers according to the map in Table 11-21.

Reading/writing of a Nexus register then requires two (2) passes through the Data-Scan (DR) path of the

JTAG state machine (see 11.12, “IEEE 1149.1 State Machine and RD/WR Sequences”).

1. The first pass through the DR selects the Nexus register to be accessed by providing an index (see

Table 11-21), and the direction (read/write). This is achieved by loading an 8-bit value into the

JTAG Data Register (DR). This register has the following format:

Table 11-44. JTAG Nexus3 Register Select

JTAG Instruction

JTAG Access Opcode

Read/Write

NEXUS-ACCESS

0xnn (hex) (programmable)

Watchpoint

Error

WPM:

TCODE = 15

source processor = 0000

watchpoint = 0010 (ARM 1)

Error:

TCODE = 8

source processor = 0000

error code = 6 (queue overrun, WPM only)

MCKO

MSEO_B

MDO[1:0]

MAC7200 bảng dữ liệu(PDF) 262 Page - Freescale Semiconductor, Inc

MAC7200 bảng dữ liệu(HTML) 262 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

bảng dữ liệu tải về

Link URL