16-bit XLP experiment, PIC24F16KA102

[Randall Young]

Howdy!,

Attempting to get FF 5.0 work on my XLP, 16bit demo board. I have the shipped demo working fine, and sending data out the serial port at 56k. Checking the schematic I believe UART2 is connect to the USB2TLL converter. I took the fuse config from the working program and tried it. An external 8 Mhz crystall is available on board for the PIC24F.

Not seeing data out the serial port at this time, please advise. Thank you!

Here's my setup in p24f_config.inc

config _FBS(BSS_OFF & BWRP_OFF)
config _FGS(GCP_OFF & GWRP_OFF)
config _FOSCSEL(FNOSC_FRCDIV & IESO_OFF)
config _FOSC(FCKSM_CSECMD & POSCFREQ_MS & OSCIOFNC_ON & POSCMOD_NONE & SOSCSEL_SOSCLP)
config _FWDT(FWDTEN_OFF & WINDIS_OFF & FWPSA_PR128 & WDTPS_PS32768)
config _FPOR(MCLRE_ON & BORV_LPBOR & BOREN_BOR3 & I2C1SEL_PRI & PWRTEN_OFF)
config _FICD(BKBUG_OFF & ICS_PGx3)
config _FDS(DSWDTEN_OFF & DSBOREN_ON & RTCOSC_SOSC & DSWDTOSC_SOSC & DSWDTPS_DSWDTPSF) //DSWDT SOSC = LPRC

.equ FREQ_OSC, (8000000*4) ;Clock (Crystal)frequency (Hz)

.equ FCY, (FREQ_OSC/2)

; Define the UART used for the operator
**.equ OPERATOR_UART, 2 ** ; 1 or 2

;;; UART1 configuration
.equ BAUDRATE1, 38400 ; Serial baudrate UART1
.equ FC1_TYPE, 1 ; 1 = XON/XOFF, 2=CTS/RTS
.equ AUTOBAUD1, 0 ; 0 = to use fixed baudrate
; 1 = Autobaud, First char after reset must be 'U' (0x55)

;;; UART2 configuration
.equ BAUDRATE2, 38400 ; Serial baudrate UART2, comment if not used
.equ FC2_TYPE, 1 ; ; 1 = XON/XOFF, 2=CTS/RTS
.equ AUTOBAUD2, 0 ; 0 = to use fixed baudrate
; 1 = Autobaud, First char after reset must be 'U' (0x55)

[Mikael Nordman]

Your config uses the internal oscillator What is its frequency ? 8 MHz?

[Randall Young]

There is a an external crystal @ 8 Mhz. I was suprised that the demo code did not use it explicitly.

I guess thats because the XLP demo application was focused on keeping the processor in the sleep state for power concerns and then spitting out data to the serial port at a very odd baud rate of 1,000,000 bps.

I only assume an internal frequency 8 mhz, in this condition, I haven't tested this. Where should I look? PIC24F clock setup is new to me, but easy to study however ... I guess what I should have simply asked is how to config the PIC24 to use the external crystall at 8 Mhz, to be correct for the 38,400 baud rate suggeted. I note that you do some math to the frequency to get it where you want in your code.

I would like the accuracy of the hw crystall for my application....

[Mikael Nordman]

Hi,
You need to use the p24fk_config.inc file.

With the following modifications it should run at 8MHz with your chip (not tested).

.equ FLASH_SIZE,     0x2100  ; Flash size in bytes without the high byte
                             ; See program memory size in the device datasheet.
.equ RAM_SIZE,       0x0600  ; Ram size in bytes
;; Check the configuration for your particular chip from the datasheet.
; For some reason the normal config macros did not work
           .pushsection __FOSCSEL.sec, code
           .global __FOSCSEL
__FOSCSEL: .pword FNOSC_PRI
           .popsection
           .pushsection __FOSC.sec, code
           .global __FOSC
__FOSC:    .pword POSCMOD_HS
           .popsection


.equ FREQ_OSC, (8000000)     ;Clock (Crystal)frequency (Hz)

; Define the UART used for the operator
.equ OPERATOR_UART, 2        ; 1 or 2

Using the PLL with external crystal has not been implemented in FlashForth.
Read chapter 9, Oscillator Configuration, in the data sheet.

[Randall Young]

I see, thanks so much for the consideration of your reply, much appreciated. I will hit chapter 9 hard.

[Randall Young]

I made the code change requested. I see that you've modified the mem spec for the chip I have (PIC24F16KA102), then setup the clock to run at 8mhz. simple as possible. The comport is assigned as #2, which seems correct. However no charatcters seen out serial port. Any other suggestions relevant?

Thanks again for you time.

[Randall Young]

I found this inside the Forth Tutorial ... Building for the PIC24FV16KM202, Section 3.3

.ifdef __24FV16KM202
.print "Customize p24f16ka_config.inc for PIC24FV16KM202"
;;; Below is the setting for max amount of ram for PIC24FV16KM202

.equ FLASH_SIZE, 0x2C00 ; Flash size in bytes without the high byte
; See program memory size in the device datasheet.
.equ RAM_SIZE, 0x0800 ; Ram size in bytes
.equ EEPROM_SIZE, 0x0200 ; Eeprom size

config FOSCSEL, FNOSC_FRCDIV & SOSCSRC_ANA & LPRCSEL_LP & IESO_OFF
config FOSC, POSCMOD_NONE & OSCIOFNC_IO & POSCFREQ_MS & SOSCSEL_SOSCLP & FCKSM_CSDCMD
config FWDT, FWDTEN_ON
config FPOR, BOREN_BOR3 & RETCFG_OFF & PWRTEN_ON & I2C1SEL_PRI & BORV_V18 & MCLRE_ON**

; ICS_PGx2 for strip-board example
; ICS_PGx1 for 5V Microstick for PIC24 K-series
config FICD, ICS_PGx1
.equ FREQ_OSC, (8000000) ;Clock (Crystal)frequency (Hz)
.endif

I was thinking about doing some testing on the PIC24 5V Microstick,, and/or swapping the PIC24FV into the XLP board...

[Randall Young]

Or in the more recent tutorial (Jacobs, 2016)

;;; Device memory sizes. Set according to your device.
;;; You can increase the addressable flash range be decreasing the addressable ram.
;;; Below is the setting for max amount of ram for PIC24FV32KA302
.equ FLASH_SIZE, 0x5800 ; Flash size in bytes without the high byte
; See program memory size in the device datasheet.
.equ RAM_SIZE, 0x0800 ; Ram size in bytes
.equ EEPROM_SIZE, 0x0200 ; Eeprom size
; For some reason the normal config macros did not work
.pushsection FOSCSEL.sec, code
.global FOSCSEL
FOSCSEL: .pword FNOSC_FRCPLL
.popsection
; Start additions for FF Tutorial board with PIC24FV32KA30x
.pushsection FOSC.sec, code
.global FOSC
FOSC: .pword OSCIOFNC_OFF
.popsection
.pushsection FICD.sec, code
.global FICD
FICD: .pword ICS_PGx2
.popsection
; End additions
.equ FREQ_OSC, (80000004) ;Clock (Crystal)frequency (Hz)*

the PIC24FV32KA302 is a good option, just in general, cheap and powerful.