From d5db9b7123e271b628fc29c16b7ebe59660ffba4 Mon Sep 17 00:00:00 2001 From: Christophe Favergeon Date: Wed, 22 Jan 2020 15:10:34 +0100 Subject: [PATCH] CMSIS-DSP:Correction for issue 218 --- Source/StatisticsFunctions/arm_var_q31.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Source/StatisticsFunctions/arm_var_q31.c b/Source/StatisticsFunctions/arm_var_q31.c index 27ff2112..0b7d4535 100644 --- a/Source/StatisticsFunctions/arm_var_q31.c +++ b/Source/StatisticsFunctions/arm_var_q31.c @@ -49,7 +49,7 @@ The input is represented in 1.31 format, which is then downshifted by 8 bits which yields 1.23, and intermediate multiplication yields a 2.46 format. The accumulator maintains full precision of the intermediate multiplication results, - but provides only a 16 guard bits. + and as a consequence has only 16 guard bits. There is no saturation on intermediate additions. If the accumulator overflows it wraps around and distorts the result. In order to avoid overflows completely the input signal must be scaled down by