UM10310_1 © NXP B.V. 2008. All rights reserved.
User manual Rev. 01 — 1 December 2008 99 of 139
NXP Semiconductors UM10310
P89LPC9321 User manual
If PGA is enabled, it will consume power. Power can be reduced by disabling the PGA. PGA can be disabled via clearing ENPGAx bit. In Power-down mode or Total Power-down mode, PGA does not function.
Table 85. PGA trim register
Register bits Contains
PGAxTRIM2X4X[3:0] trim value for 2x gain value
PGAxTRIM2X4X[7:4] trim value for 4x gain value
PGAxTRIM8X16X[3:0] trim value for 8x gain value
PGAxTRIM8X16X[7:4] trim value for16x gain value
Table 86. PGA1 Control register (PGACON1 - address FFE1h) bit allocation
Bit 76543210
Symbol ENPGA1 PGASEL11 PGASEL10 PGATRIM1 - - PGAG11 PGAG10
Reset00000000
Table 87. PGA1 Control register (PGACON1 - address FFE1h) bit description
Bit Symbol Description
1:0 PGAG11, PGAG10 PGA Gain selection bits.
00 : Gain = 2
01 : Gain = 4
10 : Gain = 8
11 : Gain = 16
3:2 - reserved
4 PGATRIM1 If set, PGA1 is grounded. If cleared, normal operation mode.
6:5 PGASEL11,
PGASEL10 PGA input channel selection
00 : CIN2B using PGA
01 : CIN2A using PGA
10 : CIN1B using PGA
11 : CIN1A using PGA
7 ENPGA1 PGA1 enable. If set, enable PGA1. If cleared, disable PGA1.
Table 88. PGA1 Control register B (PGACON1B - address FFE4h) bit allocation
Bit 76543210
Symbol-------PGAENOF
F1
Reset00000000
Table 89. PGA1 Control register B (PGACON1B - address FFE4h) bit description
Bit Symbol Description
0 PGAENOFF1 PGA offset voltage enable bit. When set, enable the offset voltage on the PGA.
1:7 - Reserved