i2clib inc

diff --git a/detpic/i2clib.asm b/detpic/i2clib.asm
new file mode 100644 (file)
index 0000000..523e43b
--- /dev/null
+++ b/detpic/i2clib.asm
@@ -0,0 +1,92 @@
+;######################################################################
+; i2clib.inc - I2C LIBRARY - IMPLEMENTATION
+;
+; See i2clib.asm for documentation of the interface to this file.
+
+ include /usr/share/gputils/header/p18f458.inc
+ radix dec
+ include ../iwjpictest/insn-aliases.inc
+
+;============================================================
+; COMMON ADMINISTRATIVE ROUTINES
+
+               udata_acs
+t              res     1
+
+               code
+
+;--------------------
+i2cs_init
+;      W               slave number            undefined
+               rcall   slave2addr2
+               mov_wf  SSPADD
+               mov_lw  0x16 ; !SSPEN, CKP(release), I2C 7-bit slave
+               mov_wf  SSPCON1
+               mov_lw  0x81 ; GCEN, SEN
+               mov_wf  SSPCON2
+               mov_lw  0x8 ; SMP(noslew), !CKE, !BF(empty)
+               mov_wf  SSPSTAT
+               bs_f    TRISB, 0
+               bs_f    TRISB, 1
+               bc_f    IPR1, SSPIP
+               bs_f    SSPCON1, SSPEN
+               bs_f    PIE1, SSPIE
+               return
+
+;--------------------
+i2cs_interrupt
+               bt_f_if0 PIR1, SSPIF
+               return
+; We have an interrupt.  What are the possibilities ?
+               mov_ff  SSPSTAT, t
+
+chkval macro mask, value, label
+               mov_fw  t
+               and_lw  mask
+               xor_lw  value
+               bra_z   label
+               endm
+                       ; bits we want to check
+                       ;  80  60  20    04    02  01
+                       ;  SMP CKE D_A   R_W   UA  BF
+                       ;  set clr data? read? clr full?
+
+               chkval  0xe3, 0x81, got_addr
+               chkval  0xe7, 0xa1, got_data_write
+               chkval  0xe7, 0xa4, sent_data_read
+
+               
+
+               mov_fw  SSPSTAT
+               and_lw  0xe7 ; all except P and S
+
+               xor_lw  0x80
+                       ; bits which might sensibly be set
+
+chkval_last equ 0
+chkval macro value, label
+               xor_lw  value ^ chkval_last
+               bra_z   label
+chkval_last equ value
+               endm
+               chkval  0x80 ;     addr  dunno 
+
+               mov_lw  0x8
+
+
+               bt_f_if0 DATA_ADDRESS, SSPSTAT
+               bra     data
+
+slave2addr
+; computes slave address in form suitable for use in i2c controller
+; actual i2c slave address is (slave number) + 0b0001000
+;      W               slave number            i2c address * 2
+               add_lw  0b0001000
+               rlc_w
+               return
+
+
+
+
+ include i2clib.inc
+ end

diff --git a/detpic/i2clib.inc b/detpic/i2clib.inc
index 5392468b0d6b4a95410e12d6c7ffce4cb0e10621..8195fbd741b0f171b1d4a836f8a0efaf1f6e6a80 100644 (file)
--- a/detpic/i2clib.inc
+++ b/detpic/i2clib.inc
@@ -1,5 +1,5 @@
 ;######################################################################
-; i2clib.inc - I2C LIBRARY, DECLARATIONS AND DOCUMENTATION
+; i2clib.inc - I2C LIBRARY - DECLARATIONS AND DOCUMENTATION
 ;
 ;
 ;============================================================
@@ -81,6 +81,7 @@ extern i2cs_init
 ;   State                      Not-in-use              Idle
 ;   W                          slave number            any
 
+;--------------------
 extern i2cs_interrupt
 extern i2cm_interrupt
 ;