From e502c75971ddfd03864b12225bb5387afad6e36b Mon Sep 17 00:00:00 2001
From: Daniel Friesel <daniel.friesel@uos.de>
Date: Fri, 11 Dec 2020 15:21:03 +0100
Subject: msp430fR5994lp: configurable uart baud rate

---
 src/arch/msp430fr5994lp/Makefile.inc     | 12 +++++++++---
 src/arch/msp430fr5994lp/driver/stdout.cc | 20 ++++++++++++--------
 2 files changed, 21 insertions(+), 11 deletions(-)

(limited to 'src')

diff --git a/src/arch/msp430fr5994lp/Makefile.inc b/src/arch/msp430fr5994lp/Makefile.inc
index e7c652a..9bc7cfe 100644
--- a/src/arch/msp430fr5994lp/Makefile.inc
+++ b/src/arch/msp430fr5994lp/Makefile.inc
@@ -9,7 +9,7 @@ MCU = msp430fr5994
 
 DEBUG_PORT ?= ttyACM0
 SERIAL_PORT ?= ttyACM1
-BAUD ?= 115200
+uart_freq ?= 115200
 
 cpu_freq ?= 16000000
 
@@ -142,7 +142,13 @@ else
 endif
 
 ifeq (${cpu_freq}, 32768)
-	BAUD=9600
+	uart_freq=9600
+endif
+
+ifneq (${uart_freq}, )
+	COMMON_FLAGS += -DF_UART=${uart_freq}UL
+else
+	COMMON_FLAGS += -DF_UART=115200UL
 endif
 
 
@@ -195,7 +201,7 @@ arch_info:
 	@echo "I2C   Freq: ${i2c_freq} Hz"
 	@echo "Counter Overflow: 65536/65535"
 	@echo "sleep_ms Overflow: 250 500"
-	@echo "Monitor: /dev/${SERIAL_PORT} ${BAUD}"
+	@echo "Monitor: /dev/${SERIAL_PORT} ${uart_freq}"
 
 gdb-server:
 	${GDBA} /opt/msp430/ti/msp430-gcc-full-linux-5.1.2.0/msp430.dat
diff --git a/src/arch/msp430fr5994lp/driver/stdout.cc b/src/arch/msp430fr5994lp/driver/stdout.cc
index 9bd196f..eaa59f8 100644
--- a/src/arch/msp430fr5994lp/driver/stdout.cc
+++ b/src/arch/msp430fr5994lp/driver/stdout.cc
@@ -17,34 +17,38 @@
 void StandardOutput::setup()
 {
 	UCA0CTLW0 |= UCSWRST;
-#if F_CPU == 16000000UL
-	// 16M / 115200 == 138.88889 -> UCOS16 = 1, UCBR0 = 16, UCBRF0 = 10, UCBRS0 = 0xf7 ("0.8751")
+#if F_CPU == 16000000UL && F_UART == 115200UL
+	// 16M / 115200 == 138.88889 -> UCOS16 = 1, UCBR0 = 16, UCBRF0 = 10, UCBRS0 = 0xf7 ("0.8751"). -0.32% / 0.32% TX error
 	UCA0CTLW0 = UCSWRST | UCSSEL__SMCLK;
 	UCA0MCTLW = UCOS16 | (10<<4) | 0xF700;
 	UCA0BR0 = 8;
-#elif F_CPU == 8000000UL
-	// 8M / 115200 == 69.444444 -> UCOS16 = 1, UCBR0 = 4, UCBRF0 = 5, UCBRS0 = 0x55 ("0.4378")
+#elif F_CPU == 8000000UL && F_UART == 115200UL
+	// 8M / 115200 == 69.444444 -> UCOS16 = 1, UCBR0 = 4, UCBRF0 = 5, UCBRS0 = 0x55 ("0.4378"). -0.8% / 0.64% TX error
 	UCA0CTLW0 = UCSWRST | UCSSEL__SMCLK;
 	UCA0MCTLW = UCOS16 | (5<<4) | 0x5500;
 	UCA0BR0 = 4;
-#elif F_CPU == 4000000UL
+#elif F_CPU == 8000000UL && F_UART == 9600UL
+	UCA0CTLW0 = UCSWRST | UCSSEL__SMCLK;
+	UCA0MCTLW = UCOS16 | (1<<4) | 0x4900;
+	UCA0BR0 = 52;
+#elif F_CPU == 4000000UL && F_UART == 115200UL
 	// 4M / 115200 == 34.722222 -> UCOS16 = 1, UCBR0 = 2, UCBRF0 = 2, UCBRS0 = 0xbb ("0.7147")
 	UCA0CTLW0 = UCSWRST | UCSSEL__SMCLK;
 	UCA0MCTLW = UCOS16 | (2<<4) | 0xbb00;
 	UCA0BR0 = 2;
-#elif F_CPU == 1000000UL
+#elif F_CPU == 1000000UL && F_UART == 115200UL
 	// 1M / 115200 == 8.6805556 -> UCOS16 = 0, UCBR0 = 8, UCBRF0 = 0, UCBRS0 = 0xd6 ("0.6667")
 	UCA0CTLW0 = UCSWRST | UCSSEL__SMCLK;
 	UCA0MCTLW = 0x5500;
 	UCA0BR0 = 8;
-#elif F_CPU == 32768UL
+#elif F_CPU == 32768UL && F_UART == 9600UL
 	// Limited to 9600 Baud
 	// 32768 / 9600 == 3.413333 -> UCOS16 = 0, UCBR0 = 3, UCBRF0 = 0, UCBRS0 = 0x92 ("0.4003")
 	UCA0CTLW0 = UCSWRST | UCSSEL__SMCLK;
 	UCA0MCTLW = 0x9200;
 	UCA0BR0 = 3;
 #else
-#error Unsupported F_CPU
+#error Unsupported F_CPU and F_UART combination
 #endif
 
 	UCA0IRCTL = 0;
-- 
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