fix: typo in parameter name

freqMHz → freqHz in SPI, TWI, and USART:
they all expect the frequency in hertz, not mega-hertz.

Author: urish

src/peripherals/spi.ts

@@ -50,7 +50,7 @@ export class AVRSPI {
     enableMask: SPCR_SPIE,
   };
 
-  constructor(private cpu: CPU, private config: SPIConfig, private freqMHz: number) {
+  constructor(private cpu: CPU, private config: SPIConfig, private freqHz: number) {
     const { SPCR, SPSR, SPDR } = config;
     cpu.writeHooks[SPDR] = (value: u8) => {
       if (!(cpu.data[SPCR] & SPCR_SPE)) {
@@ -130,6 +130,6 @@ export class AVRSPI {
    * In slave mode, the frequency can be as high as F(osc) / 4.
    */
   get spiFrequency() {
-    return this.freqMHz / this.clockDivider;
+    return this.freqHz / this.clockDivider;
   }
 }

src/peripherals/twi.ts

@@ -104,7 +104,7 @@ export class AVRTWI {
     enableMask: TWCR_TWIE,
   };
 
-  constructor(private cpu: CPU, private config: TWIConfig, private freqMHz: number) {
+  constructor(private cpu: CPU, private config: TWIConfig, private freqHz: number) {
     this.updateStatus(STATUS_TWI_IDLE);
     this.cpu.writeHooks[config.TWCR] = (value) => {
       this.cpu.data[config.TWCR] = value;
@@ -149,7 +149,7 @@ export class AVRTWI {
   }
 
   get sclFrequency() {
-    return this.freqMHz / (16 + 2 * this.cpu.data[this.config.TWBR] * this.prescaler);
+    return this.freqHz / (16 + 2 * this.cpu.data[this.config.TWBR] * this.prescaler);
   }
 
   completeStart() {

src/peripherals/usart.ts

@@ -87,7 +87,7 @@ export class AVRUSART {
     enableMask: UCSRB_TXCIE,
   };
 
-  constructor(private cpu: CPU, private config: USARTConfig, private freqMHz: number) {
+  constructor(private cpu: CPU, private config: USARTConfig, private freqHz: number) {
     this.reset();
     this.cpu.writeHooks[config.UCSRA] = (value) => {
       cpu.data[config.UCSRA] = value;
@@ -142,7 +142,7 @@ export class AVRUSART {
   }
 
   get baudRate() {
-    return Math.floor(this.freqMHz / (this.multiplier * (1 + this.UBRR)));
+    return Math.floor(this.freqHz / (this.multiplier * (1 + this.UBRR)));
   }
 
   get bitsPerChar() {