RM5261-200-QI PMC-Sierra Inc, RM5261-200-QI Datasheet - Page 25

• Manufacturer Part Number: RM5261-200-QI
• Description: RM5261 Microprocessor with 64-Bit System Bus Data Sheet Released
• Manufacturer: PMC-Sierra Inc

Proprietary and Confidential to PMC-Sierra, Inc and for its Customer’s Internal Use
Document ID: PMC-2002241, Issue 1
3.32 Boot-Time Modes
Immediately after the VccOK signal is asserted, the processor reads a serial bit stream of 256 bits
to initialize all the fundamental operational modes. ModeClock run continuously from the
assertion of VccOK.
The boot-time serial mode stream is defined in Table 4. Bit 0 is the bit presented to the processor
as the first bit in the stream when VccOK is asserted. Bit 255 is the last bit transferred.
Table 4 Boot-Time Mode Bit Stream
Mode
bit
0
4:1
7:5
8
10:9
11
12
Description
reserved (must be zero)
Write-back data rate
Pclock to SysClock Multiplier
Specifies byte ordering. Logically ORed
with BigEndian input signal.
Non-Block Write Protocol
Timer Interrupt Enable/Disable
Reserved: Must be zero
0: DDDD
1: DDxDDx
2: DDxxDDxx
3: DxDxDxDx
4: DDxxxDDxxx
5: DDxxxxDDxxxx
6: DxxDxxDxxDxx
7: DDxxxxxxDDxxxxxx
8: DxxxDxxxDxxxDxxx
9-15 reserved
Mode Bits 7:5 Mode Bit 20=0 Mode Bit 20=1
000
001
010
011
100
101
110
111
0: Little endian
1: Big endian
00: R4000 compatible
01: reserved
10: pipelined
11: write re-issue
0: Enable the timer interrupt on Int5*
1: Disable the timer interrupt on Int5*
Multiply by 9
Multiply by 8
Multiply by 6
Multiply by 7
Multiply by 5
Multiply by 2
Multiply by 3
Multiply by 4
Multiply by 4.5
Multiply by 2.5
Multiply by 3.5
RM5261™ Microprocessor with 64-Bit System Bus Data Sheet
n/a
n/a
n/a
n/a
n/a
Mode
bit
14:13
15
17:16
19:18
20
21
255:22
Description
Output driver strength - 100% = fastest
Reserved: Must be zero
System configuration identifiers - software
visible in Config[21..20] register
Reserved: Must be zero
Select Pclock to SysClock Multiply Mode
External Bus Width
Reserved: Must be zero
00: 67% strength
01: 50% strength
10: 100% strength
11: 83% strength
0: Integer Multipliers
1: Half-Integer Multipliers
0: 64-bit
1: 32-bit
Released
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