Texas Instruments TMS320C80, Руководство пользователя

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Obtaining Device-Specific Information
2-3 Programming for Compatibility
2.2 Obtaining Device-Specific Information
Device-specific information can be obtained by your software.
This information can help you effectively use all available PPs
and properly initialize each PP’s stack pointer.
2.2.1 Determining the Device that is Executing your Software (MP)
An MP-resident program can determine which device it is running
on by reading the MP’s CONFIG register, which is shown in
Figure 2–1. The 4-bit type field in bits 15–12 of the CONFIG reg-
ister is hardwired to the value 0000
2
in the ’C80, and to the value
0010
2
in the ’C82.
Figure 2–1. The Type Field in the MP CONFIG Register
31 16 15 12 11 0
ÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉ
Type
†
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
†
Type = 0000
2
in the ’C80; Type = 0010
2
in the ’C82
2.2.2 Determining the Device that is Executing your Software (PP)
PP software can determine which device it is running on by read-
ing the M field (bits 15–8) in the comm register, which is shown
in Figure 2–2. The M field equals 00000000
2
in the ’C80 and
00000001
2
in the ’C82.
Figure 2–2. The PP’s comm Register
31 30 29 28 27 16 15 8 7 4 3 2 1 0
H S Q P Reserved M
†
Reserved R PP#
†
M=00000000
2
in the ’C80; M=00000001
2
in the ’C82
Notes:
1) In order to provide backward compatibility for preproduction
’C80 devices (silicon revisions 1, 2, and 3), your software
should write a value of 0 to the comm register to initialize the
M field before attempting to read it. In preproduction ’C80
devices, bit 8 of the comm register is a read/write bit whose
value is undefined immediately following reset.
2) The M field will be used to identify future versions of the ’C8x,
so make sure your software checks all bits in the M field to
properly identify the device.